playwright/browser_patches/webkit/patches/bootstrap.diff

diff --git a/Source/JavaScriptCore/CMakeLists.txt b/Source/JavaScriptCore/CMakeLists.txt
index 91e427c30c51163edd9f106d42f95e09d02be9c4..b7a591467cea135960be9ac4d8fbaadcdcdcaf5b 100644
--- a/Source/JavaScriptCore/CMakeLists.txt
+++ b/Source/JavaScriptCore/CMakeLists.txt
@@ -1144,16 +1144,20 @@ set(JavaScriptCore_INSPECTOR_DOMAINS
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Animation.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/ApplicationCache.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Audit.json
+    ${JAVASCRIPTCORE_DIR}/inspector/protocol/Browser.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/CSS.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Canvas.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Console.json
+    ${JAVASCRIPTCORE_DIR}/inspector/protocol/Dialog.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/DOM.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/DOMDebugger.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/DOMStorage.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Database.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Debugger.json
+    ${JAVASCRIPTCORE_DIR}/inspector/protocol/Emulation.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/GenericTypes.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Heap.json
+    ${JAVASCRIPTCORE_DIR}/inspector/protocol/Input.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Inspector.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/LayerTree.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Network.json
diff --git a/Source/JavaScriptCore/DerivedSources.make b/Source/JavaScriptCore/DerivedSources.make
index e2a36fa8764909abfd0e1896d3a9a7c361f1b23a..e3ed01ae7cf8ce68a4fd8308e0ea2819638a78d3 100644
--- a/Source/JavaScriptCore/DerivedSources.make
+++ b/Source/JavaScriptCore/DerivedSources.make
@@ -241,16 +241,20 @@ INSPECTOR_DOMAINS := \
     $(JavaScriptCore)/inspector/protocol/Animation.json \
     $(JavaScriptCore)/inspector/protocol/ApplicationCache.json \
     $(JavaScriptCore)/inspector/protocol/Audit.json \
+    $(JavaScriptCore)/inspector/protocol/Browser.json \
     $(JavaScriptCore)/inspector/protocol/CSS.json \
     $(JavaScriptCore)/inspector/protocol/Canvas.json \
     $(JavaScriptCore)/inspector/protocol/Console.json \
+    $(JavaScriptCore)/inspector/protocol/Dialog.json \
     $(JavaScriptCore)/inspector/protocol/DOM.json \
     $(JavaScriptCore)/inspector/protocol/DOMDebugger.json \
     $(JavaScriptCore)/inspector/protocol/DOMStorage.json \
     $(JavaScriptCore)/inspector/protocol/Database.json \
     $(JavaScriptCore)/inspector/protocol/Debugger.json \
+    $(JavaScriptCore)/inspector/protocol/Emulation.json \
     $(JavaScriptCore)/inspector/protocol/GenericTypes.json \
     $(JavaScriptCore)/inspector/protocol/Heap.json \
+    $(JavaScriptCore)/inspector/protocol/Input.json \
     $(JavaScriptCore)/inspector/protocol/Inspector.json \
     $(JavaScriptCore)/inspector/protocol/LayerTree.json \
     $(JavaScriptCore)/inspector/protocol/Network.json \
diff --git a/Source/JavaScriptCore/bindings/ScriptValue.cpp b/Source/JavaScriptCore/bindings/ScriptValue.cpp
index dece6ac51e3a85b1e094e405effc6203887ddfd4..9bf7519d894eceb06b40d754c4fb7940399eba84 100644
--- a/Source/JavaScriptCore/bindings/ScriptValue.cpp
+++ b/Source/JavaScriptCore/bindings/ScriptValue.cpp
@@ -81,7 +81,10 @@ static RefPtr<JSON::Value> jsToInspectorValue(JSGlobalObject* globalObject, JSVa
         PropertyNameArray propertyNames(vm, PropertyNameMode::Strings, PrivateSymbolMode::Exclude);
         object.methodTable(vm)->getOwnPropertyNames(&object, globalObject, propertyNames, EnumerationMode());
         for (auto& name : propertyNames) {
-            auto inspectorValue = jsToInspectorValue(globalObject, object.get(globalObject, name), maxDepth);
+            JSValue childValue = object.get(globalObject, name);
+            if (childValue.isUndefined())
+                continue;
+            auto inspectorValue = jsToInspectorValue(globalObject, childValue, maxDepth);
             if (!inspectorValue)
                 return nullptr;
             inspectorObject->setValue(name.string(), WTFMove(inspectorValue));
diff --git a/Source/JavaScriptCore/inspector/IdentifiersFactory.cpp b/Source/JavaScriptCore/inspector/IdentifiersFactory.cpp
index 95cd87b01b15cb8667e57bc5bb51a71f06bc3760..0481fa93227f297be9d9cf000c5a72235956a390 100644
--- a/Source/JavaScriptCore/inspector/IdentifiersFactory.cpp
+++ b/Source/JavaScriptCore/inspector/IdentifiersFactory.cpp
@@ -30,14 +30,21 @@
 namespace Inspector {
 
 namespace {
+static uint64_t s_processID = 0;
 static long s_lastUsedIdentifier = 0;
 }
 
 static String addPrefixToIdentifier(const String& identifier)
 {
-    return makeString("0.", identifier);
+    return makeString(s_processID, ".", identifier);
 }
 
+void IdentifiersFactory::initializeWithProcessID(uint64_t processID) {
+    ASSERT(!s_processID);
+    s_processID = processID;
+}
+
+
 String IdentifiersFactory::createIdentifier()
 {
     return addPrefixToIdentifier(String::number(++s_lastUsedIdentifier));
diff --git a/Source/JavaScriptCore/inspector/IdentifiersFactory.h b/Source/JavaScriptCore/inspector/IdentifiersFactory.h
index eb25aedee4cd9ebe007e06c2515b37ee095b06f4..badf6559595c8377db1089ca3c25008e1be2c8f1 100644
--- a/Source/JavaScriptCore/inspector/IdentifiersFactory.h
+++ b/Source/JavaScriptCore/inspector/IdentifiersFactory.h
@@ -31,6 +31,7 @@ namespace Inspector {
 
 class JS_EXPORT_PRIVATE IdentifiersFactory {
 public:
+    static void initializeWithProcessID(uint64_t);
     static String createIdentifier();
     static String requestId(unsigned long identifier);
 };
diff --git a/Source/JavaScriptCore/inspector/InjectedScript.cpp b/Source/JavaScriptCore/inspector/InjectedScript.cpp
index cc849f051fa40518a9d1a03429bc2b4dbcfb3102..11b05346f6098fa23f51ba9abc1af0e0e60a626c 100644
--- a/Source/JavaScriptCore/inspector/InjectedScript.cpp
+++ b/Source/JavaScriptCore/inspector/InjectedScript.cpp
@@ -287,9 +287,13 @@ RefPtr<Protocol::Runtime::RemoteObject> InjectedScript::wrapObject(JSC::JSValue
     auto callResult = callFunctionWithEvalEnabled(wrapFunction);
     if (!callResult)
         return nullptr;
+    auto callResultValue = callResult.value();
+    // callResultValue could be missing if the execution was terminated
+    if (!callResultValue)
+        return nullptr;
 
     RefPtr<JSON::Object> resultObject;
-    bool castSucceeded = toInspectorValue(globalObject(), callResult.value())->asObject(resultObject);
+    bool castSucceeded = toInspectorValue(globalObject(), callResultValue)->asObject(resultObject);
     ASSERT_UNUSED(castSucceeded, castSucceeded);
 
     return BindingTraits<Protocol::Runtime::RemoteObject>::runtimeCast(resultObject);
diff --git a/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.cpp b/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.cpp
index 038cb646d31706905deff8935040d63c0afd00f9..2fca7b043f15a8cce3819cc827912fb719a345db 100644
--- a/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.cpp
+++ b/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.cpp
@@ -102,7 +102,7 @@ void BackendDispatcher::registerDispatcherForDomain(const String& domain, Supple
     m_dispatchers.set(domain, dispatcher);
 }
 
-void BackendDispatcher::dispatch(const String& message)
+BackendDispatcher::DispatchResult BackendDispatcher::dispatch(const String& message, Mode mode, Interceptor&& interceptor)
 {
     Ref<BackendDispatcher> protect(*this);
 
@@ -120,29 +120,32 @@ void BackendDispatcher::dispatch(const String& message)
         if (!JSON::Value::parseJSON(message, parsedMessage)) {
             reportProtocolError(ParseError, "Message must be in JSON format"_s);
             sendPendingErrors();
-            return;
+            return DispatchResult::Finished;
         }
 
         if (!parsedMessage->asObject(messageObject)) {
             reportProtocolError(InvalidRequest, "Message must be a JSONified object"_s);
             sendPendingErrors();
-            return;
+            return DispatchResult::Finished;
         }
 
         RefPtr<JSON::Value> requestIdValue;
         if (!messageObject->getValue("id"_s, requestIdValue)) {
             reportProtocolError(InvalidRequest, "'id' property was not found"_s);
             sendPendingErrors();
-            return;
+            return DispatchResult::Finished;
         }
 
         if (!requestIdValue->asInteger(requestId)) {
             reportProtocolError(InvalidRequest, "The type of 'id' property must be integer"_s);
             sendPendingErrors();
-            return;
+            return DispatchResult::Finished;
         }
     }
 
+    if (interceptor && interceptor(messageObject) == DispatchResult::Finished)
+        return DispatchResult::Finished;
+
     {
         // We could be called re-entrantly from a nested run loop, so restore the previous id.
         SetForScope<Optional<long>> scopedRequestId(m_currentRequestId, requestId);
@@ -151,29 +154,31 @@ void BackendDispatcher::dispatch(const String& message)
         if (!messageObject->getValue("method"_s, methodValue)) {
             reportProtocolError(InvalidRequest, "'method' property wasn't found"_s);
             sendPendingErrors();
-            return;
+            return DispatchResult::Finished;
         }
 
         String methodString;
         if (!methodValue->asString(methodString)) {
             reportProtocolError(InvalidRequest, "The type of 'method' property must be string"_s);
             sendPendingErrors();
-            return;
+            return DispatchResult::Finished;
         }
 
         Vector<String> domainAndMethod = methodString.splitAllowingEmptyEntries('.');
         if (domainAndMethod.size() != 2 || !domainAndMethod[0].length() || !domainAndMethod[1].length()) {
             reportProtocolError(InvalidRequest, "The 'method' property was formatted incorrectly. It should be 'Domain.method'"_s);
             sendPendingErrors();
-            return;
+            return DispatchResult::Finished;
         }
 
         String domain = domainAndMethod[0];
         SupplementalBackendDispatcher* domainDispatcher = m_dispatchers.get(domain);
         if (!domainDispatcher) {
+            if (mode == Mode::ContinueIfDomainIsMissing)
+                return DispatchResult::Continue;
             reportProtocolError(MethodNotFound, "'" + domain + "' domain was not found");
             sendPendingErrors();
-            return;
+            return DispatchResult::Finished;
         }
 
         String method = domainAndMethod[1];
@@ -182,6 +187,7 @@ void BackendDispatcher::dispatch(const String& message)
         if (m_protocolErrors.size())
             sendPendingErrors();
     }
+    return DispatchResult::Finished;
 }
 
 // FIXME: remove this function when legacy InspectorObject symbols are no longer needed <http://webkit.org/b/179847>.
diff --git a/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.h b/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.h
index 95d9d81188e735e8f1b70cc0deee2682cb6714f0..4c67ce34302f74e0d07f64ae53a4eaf18df6669a 100644
--- a/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.h
+++ b/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.h
@@ -82,7 +82,11 @@ public:
     };
 
     void registerDispatcherForDomain(const String& domain, SupplementalBackendDispatcher*);
-    void dispatch(const String& message);
+
+    enum class DispatchResult { Finished, Continue };
+    enum class Mode { FailIfDomainIsMissing, ContinueIfDomainIsMissing };
+    using Interceptor = WTF::Function<DispatchResult(const RefPtr<JSON::Object>&)>;
+    DispatchResult dispatch(const String& message, Mode mode = Mode::FailIfDomainIsMissing, Interceptor&& interceptor = Interceptor());
 
     // Note that 'unused' is a workaround so the compiler can pick the right sendResponse based on arity.
     // When <http://webkit.org/b/179847> is fixed or this class is renamed for the JSON::Object case,
diff --git a/Source/JavaScriptCore/inspector/InspectorFrontendRouter.cpp b/Source/JavaScriptCore/inspector/InspectorFrontendRouter.cpp
index d408d364f1986983161f9d44efbc8bc6f6898676..1375ce9990f0c63d7e6f33ee62930051d6cd44cb 100644
--- a/Source/JavaScriptCore/inspector/InspectorFrontendRouter.cpp
+++ b/Source/JavaScriptCore/inspector/InspectorFrontendRouter.cpp
@@ -49,7 +49,7 @@ void FrontendRouter::connectFrontend(FrontendChannel& connection)
 void FrontendRouter::disconnectFrontend(FrontendChannel& connection)
 {
     if (!m_connections.contains(&connection)) {
-        ASSERT_NOT_REACHED();
+        ASSERT(m_connections.isEmpty());
         return;
     }
 
diff --git a/Source/JavaScriptCore/inspector/InspectorTarget.cpp b/Source/JavaScriptCore/inspector/InspectorTarget.cpp
index 0cc2127c9c12c2d82dea9550bad73f4ffb99ba24..8ca65cc042d435cbc0e05dcc5c5dfc958eb24f5a 100644
--- a/Source/JavaScriptCore/inspector/InspectorTarget.cpp
+++ b/Source/JavaScriptCore/inspector/InspectorTarget.cpp
@@ -44,6 +44,8 @@ void InspectorTarget::resume()
     ASSERT(m_isPaused);
     m_isPaused = false;
 
+    willResume();
+
     if (m_resumeCallback) {
         m_resumeCallback();
         m_resumeCallback = nullptr;
@@ -52,7 +54,6 @@ void InspectorTarget::resume()
 
 void InspectorTarget::setResumeCallback(WTF::Function<void()>&& callback)
 {
-    ASSERT(!m_resumeCallback);
     m_resumeCallback = WTFMove(callback);
 }
 
diff --git a/Source/JavaScriptCore/inspector/InspectorTarget.h b/Source/JavaScriptCore/inspector/InspectorTarget.h
index 4b95964db4d902b4b7f4b0b4c40afea51654ff2f..966a5927702b65edb343369decafda7fc83eaec7 100644
--- a/Source/JavaScriptCore/inspector/InspectorTarget.h
+++ b/Source/JavaScriptCore/inspector/InspectorTarget.h
@@ -56,8 +56,12 @@ public:
     virtual void connect(FrontendChannel::ConnectionType) = 0;
     virtual void disconnect() = 0;
     virtual void sendMessageToTargetBackend(const String&) = 0;
+    virtual void activate(String& error) { error = "Target cannot be activated"; }
+    virtual void close(String& error, bool /* runBeforeUnload */) { error = "Target cannot be closed"; }
 
 private:
+    virtual void willResume() { }
+
     WTF::Function<void()> m_resumeCallback;
     bool m_isPaused { false };
 };
diff --git a/Source/JavaScriptCore/inspector/agents/InspectorTargetAgent.cpp b/Source/JavaScriptCore/inspector/agents/InspectorTargetAgent.cpp
index 8fcb5a1e55750d325a84824d86c49cfe6fb04268..ed2525df326bfe649793701a112eefa30952e375 100644
--- a/Source/JavaScriptCore/inspector/agents/InspectorTargetAgent.cpp
+++ b/Source/JavaScriptCore/inspector/agents/InspectorTargetAgent.cpp
@@ -87,6 +87,28 @@ void InspectorTargetAgent::sendMessageToTarget(ErrorString& errorString, const S
     target->sendMessageToTargetBackend(message);
 }
 
+void InspectorTargetAgent::activate(ErrorString& errorString, const String& targetId)
+{
+    InspectorTarget* target = m_targets.get(targetId);
+    if (!target) {
+        errorString = "Missing target for given targetId"_s;
+        return;
+    }
+
+    target->activate(errorString);
+}
+
+void InspectorTargetAgent::close(ErrorString& errorString, const String& targetId, const bool* runBeforeUnload)
+{
+    InspectorTarget* target = m_targets.get(targetId);
+    if (!target) {
+        errorString = "Missing target for given targetId"_s;
+        return;
+    }
+
+    target->close(errorString, runBeforeUnload && *runBeforeUnload);
+}
+
 void InspectorTargetAgent::sendMessageFromTargetToFrontend(const String& targetId, const String& message)
 {
     ASSERT_WITH_MESSAGE(m_targets.get(targetId), "Sending a message from an untracked target to the frontend.");
@@ -144,7 +166,17 @@ void InspectorTargetAgent::targetDestroyed(InspectorTarget& target)
     if (!m_isConnected)
         return;
 
-    m_frontendDispatcher->targetDestroyed(target.identifier());
+    m_frontendDispatcher->targetDestroyed(target.identifier(), false);
+}
+
+void InspectorTargetAgent::targetCrashed(InspectorTarget& target)
+{
+    m_targets.remove(target.identifier());
+
+    if (!m_isConnected)
+        return;
+
+    m_frontendDispatcher->targetDestroyed(target.identifier(), true);
 }
 
 void InspectorTargetAgent::didCommitProvisionalTarget(const String& oldTargetID, const String& committedTargetID)
@@ -159,6 +191,18 @@ void InspectorTargetAgent::didCommitProvisionalTarget(const String& oldTargetID,
     m_frontendDispatcher->didCommitProvisionalTarget(oldTargetID, committedTargetID);
 }
 
+void InspectorTargetAgent::ensureConnected(const String& targetID)
+{
+    if (!m_isConnected)
+        return;
+
+    auto* target = m_targets.get(targetID);
+    if (!target)
+        return;
+
+    target->connect(connectionType());
+}
+
 FrontendChannel::ConnectionType InspectorTargetAgent::connectionType() const
 {
     return m_router.hasLocalFrontend() ? Inspector::FrontendChannel::ConnectionType::Local : Inspector::FrontendChannel::ConnectionType::Remote;
diff --git a/Source/JavaScriptCore/inspector/agents/InspectorTargetAgent.h b/Source/JavaScriptCore/inspector/agents/InspectorTargetAgent.h
index 1eb7abb2fa21d7a8ec0833160f53e5c523ec4317..7709bcc2ec69aab0589ca1b954db1fb241bb583b 100644
--- a/Source/JavaScriptCore/inspector/agents/InspectorTargetAgent.h
+++ b/Source/JavaScriptCore/inspector/agents/InspectorTargetAgent.h
@@ -52,15 +52,21 @@ public:
     void setPauseOnStart(ErrorString&, bool pauseOnStart) override;
     void resume(ErrorString&, const String& targetId) override;
     void sendMessageToTarget(ErrorString&, const String& targetId, const String& message) final;
+    void activate(ErrorString&, const String& targetId) override;
+    void close(ErrorString&, const String& targetId, const bool* runBeforeUnload) override;
 
     // Target lifecycle.
     void targetCreated(InspectorTarget&);
     void targetDestroyed(InspectorTarget&);
+    void targetCrashed(InspectorTarget&);
     void didCommitProvisionalTarget(const String& oldTargetID, const String& committedTargetID);
+    void ensureConnected(const String& targetID);
 
     // Target messages.
     void sendMessageFromTargetToFrontend(const String& targetId, const String& message);
 
+    bool isConnected() { return m_isConnected; }
+
 private:
     // FrontendChannel
     FrontendChannel::ConnectionType connectionType() const;
diff --git a/Source/JavaScriptCore/inspector/protocol/Browser.json b/Source/JavaScriptCore/inspector/protocol/Browser.json
new file mode 100644
index 0000000000000000000000000000000000000000..d4f5cbc813facbd8036c0be46304e4a607cbcb79
--- /dev/null
+++ b/Source/JavaScriptCore/inspector/protocol/Browser.json
@@ -0,0 +1,211 @@
+{
+    "domain": "Browser",
+    "availability": ["web"],
+    "types": [
+        {
+            "id": "ContextID",
+            "type": "string",
+            "description": "Id of Browser context."
+        },
+        {
+            "id": "PageProxyID",
+            "type": "string",
+            "description": "Id of WebPageProxy."
+        },
+        {
+            "id": "PageProxyInfo",
+            "type": "object",
+            "description": "Tab info object",
+            "properties": [
+                { "name": "pageProxyId", "$ref": "PageProxyID" },
+                { "name": "browserContextId", "$ref": "ContextID", "description": "Unique identifier of the context." },
+                { "name": "openerId", "$ref": "PageProxyID", "optional": true, "description": "Unique identifier of the opening page. Only set for pages created by window.open()." }
+            ]
+        },
+        {
+            "id": "CookieSameSitePolicy",
+            "type": "string",
+            "enum": ["None", "Lax", "Strict"],
+            "description": "Same-Site policy of a cookie."
+        },
+        {
+            "id": "Cookie",
+            "type": "object",
+            "description": "Cookie object",
+            "properties": [
+                { "name": "name", "type": "string", "description": "Cookie name." },
+                { "name": "value", "type": "string", "description": "Cookie value." },
+                { "name": "domain", "type": "string", "description": "Cookie domain." },
+                { "name": "path", "type": "string", "description": "Cookie path." },
+                { "name": "expires", "type": "number", "description": "Cookie expires." },
+                { "name": "httpOnly", "type": "boolean", "description": "True if cookie is http-only." },
+                { "name": "secure", "type": "boolean", "description": "True if cookie is secure." },
+                { "name": "session", "type": "boolean", "description": "True if cookie is session cookie." },
+                { "name": "sameSite", "$ref": "CookieSameSitePolicy", "description": "Cookie Same-Site policy." }
+            ]
+        },
+        {
+            "id": "SetCookieParam",
+            "type": "object",
+            "description": "Cookie object",
+            "properties": [
+                { "name": "name", "type": "string", "description": "Cookie name." },
+                { "name": "value", "type": "string", "description": "Cookie value." },
+                { "name": "domain", "type": "string", "description": "Cookie domain." },
+                { "name": "path", "type": "string", "description": "Cookie path." },
+                { "name": "expires", "type": "number", "optional": true, "description": "Cookie expires." },
+                { "name": "httpOnly", "type": "boolean", "optional": true, "description": "True if cookie is http-only." },
+                { "name": "secure", "type": "boolean", "optional": true, "description": "True if cookie is secure." },
+                { "name": "session", "type": "boolean", "optional": true, "description": "True if cookie is session cookie." },
+                { "name": "sameSite", "$ref": "CookieSameSitePolicy", "optional": true, "description": "Cookie Same-Site policy." }
+            ]
+        },
+        {
+            "id": "Geolocation",
+            "type": "object",
+            "description": "Geolocation",
+            "properties": [
+                { "name": "timestamp", "type": "number", "description": "Mock latitude" },
+                { "name": "latitude", "type": "number", "description": "Mock latitude" },
+                { "name": "longitude", "type": "number", "description": "Mock longitude" },
+                { "name": "accuracy", "type": "number", "description": "Mock accuracy" }
+            ]
+        }
+    ],
+    "commands": [
+        {
+            "name": "close",
+            "async": true,
+            "description": "Close browser."
+        },
+        {
+            "name": "createContext",
+            "description": "Creates new ephemeral browser context.",
+            "returns": [
+                { "name": "browserContextId", "$ref": "ContextID", "description": "Unique identifier of the context." }
+            ]
+        },
+        {
+            "name": "deleteContext",
+            "async": true,
+            "description": "Deletes browser context previously created with createContect. The command will automatically close all pages that use the context.",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "description": "Identifier of the context to delete." }
+            ]
+        },
+        {
+            "name": "createPage",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "JSON Inspector Protocol message (command) to be dispatched on the backend." }
+            ],
+            "returns": [
+                { "name": "pageProxyId", "$ref": "PageProxyID", "description": "Unique identifier of the page proxy." }
+            ]
+        },
+        {
+            "name": "navigate",
+            "async": true,
+            "description": "Navigates current page to the given URL.",
+            "parameters": [
+                { "name": "url", "type": "string", "description": "URL to navigate the page to." },
+                { "name": "pageProxyId", "$ref": "PageProxyID", "description": "Unique identifier of the page proxy." },
+                { "name": "frameId", "$ref": "Network.FrameId", "optional": true, "description": "Id of the frame to navigate."},
+                { "name": "referrer", "type": "string", "optional": true, "description": "Referrer URL." }
+            ],
+            "returns": [
+                { "name": "loaderId", "$ref": "Network.LoaderId", "optional": true, "description": "Identifier of the loader associated with the navigation." }
+            ]
+        },
+        {
+            "name": "setIgnoreCertificateErrors",
+            "description": "Change whether all certificate errors should be ignored.",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "Browser context id." },
+                { "name": "ignore", "type": "boolean" }
+            ]
+        },
+        {
+            "name": "getAllCookies",
+            "description": "Returns all cookies in the given browser context.",
+            "async": true,
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "Browser context id." }
+            ],
+            "returns": [
+                { "name": "cookies", "type": "array", "items": { "$ref": "Cookie" }, "description": "Cookies." }
+            ]
+        },
+        {
+            "name": "setCookies",
+            "description": "Sets cookies in the given browser context.",
+            "async": true,
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "Browser context id." },
+                { "name": "cookies", "type": "array", "items": { "$ref": "SetCookieParam" }, "description": "Cookies." }
+            ]
+        },
+        {
+            "name": "deleteAllCookies",
+            "description": "Deletes cookies in the given browser context.",
+            "async": true,
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "Browser context id." }
+            ]
+        },
+        {
+            "name": "setGeolocationOverride",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "Browser context id." },
+                { "name": "geolocation", "$ref": "Geolocation", "optional": true, "description": "Geolocation to set, if missing emulates position unavailable." }
+            ],
+            "description": "Overrides the geolocation position or error."
+        },
+        {
+            "name": "grantPermissions",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "Browser context id." },
+                { "name": "origin", "type": "string" },
+                { "name": "permissions", "type": "array", "items": { "type": "string" } }
+            ],
+            "description": "Overrides the permissions."
+        },
+        {
+            "name": "resetPermissions",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "Browser context id." }
+            ],
+            "description": "Clears permission overrides."
+        },
+        {
+            "name": "setLanguages",
+            "description": "Allows to set locale language for context.",
+            "parameters": [
+                { "name": "languages", "type": "array", "items": { "type": "string" } },
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "Browser context id." }
+            ]
+        }
+    ],
+    "events": [
+        {
+            "name": "pageProxyCreated",
+            "parameters": [
+                { "name": "pageProxyInfo", "$ref": "PageProxyInfo" }
+            ]
+        },
+        {
+            "name": "pageProxyDestroyed",
+            "parameters": [
+                { "name": "pageProxyId", "$ref": "PageProxyID" }
+            ]
+        },
+        {
+            "name": "provisionalLoadFailed",
+            "description": "Fired when provisional load fails.",
+            "parameters": [
+                { "name": "pageProxyId", "$ref": "PageProxyID", "description": "Unique identifier of the page proxy." },
+                { "name": "loaderId", "$ref": "Network.LoaderId", "description": "Identifier of the loader associated with the navigation." },
+                { "name": "error", "type": "string", "description": "Localized error string." }
+            ]
+        }
+    ]
+}
diff --git a/Source/JavaScriptCore/inspector/protocol/DOM.json b/Source/JavaScriptCore/inspector/protocol/DOM.json
index 38cb48bedf2b168149ff79423b7fafc1e63ce8b3..e3d044934f5a0dc2331534439daa53116019548f 100644
--- a/Source/JavaScriptCore/inspector/protocol/DOM.json
+++ b/Source/JavaScriptCore/inspector/protocol/DOM.json
@@ -79,6 +79,16 @@
                 { "name": "value", "type": "string", "description": "The value that is resolved to with this data binding relationship." }
             ]
         },
+        {
+          "id": "Rect",
+          "type": "object",
+          "properties": [
+            { "name": "x", "type": "integer", "description": "X coordinate" },
+            { "name": "y", "type": "integer", "description": "Y coordinate" },
+            { "name": "width", "type": "integer", "description": "Rectangle width" },
+            { "name": "height", "type": "integer", "description": "Rectangle height" }
+      ]
+        },
         {
             "id": "EventListener",
             "type": "object",
@@ -167,6 +177,16 @@
                 { "name": "borderColor", "$ref": "RGBAColor", "optional": true, "description": "The border highlight fill color (default: transparent)." },
                 { "name": "marginColor", "$ref": "RGBAColor", "optional": true, "description": "The margin highlight fill color (default: transparent)." }
             ]
+        },
+        {
+            "id": "FilePayload",
+            "type": "object",
+            "description": "Data to construct File object.",
+            "properties": [
+                { "name": "name", "type": "string", "description": "File name." },
+                { "name": "type", "type": "string", "description": "File type." },
+                { "name": "data", "type": "string", "description": "Base64-encoded file data." }
+            ]
         }
     ],
     "commands": [
@@ -481,7 +501,9 @@
             "name": "resolveNode",
             "description": "Resolves JavaScript node object for given node id.",
             "parameters": [
-                { "name": "nodeId", "$ref": "NodeId", "description": "Id of the node to resolve." },
+                { "name": "nodeId", "$ref": "NodeId", "optional": true, "description": "Id of the node to resolve." },
+                { "name": "objectId", "$ref": "Runtime.RemoteObjectId", "optional": true, "description": "Source element handle." },
+                { "name": "executionContextId", "$ref": "Runtime.ExecutionContextId", "optional": true, "description": "Specifies in which execution context to adopt to." },
                 { "name": "objectGroup", "type": "string", "optional": true, "description": "Symbolic group name that can be used to release multiple objects." }
             ],
             "returns": [
@@ -542,6 +564,45 @@
             "parameters": [
                 { "name": "allow", "type": "boolean" }
             ]
+        },
+        {
+            "name": "describeNode",
+            "description": "Returns node description.",
+            "parameters": [
+                { "name": "objectId", "$ref": "Runtime.RemoteObjectId", "description": "JavaScript object id of the node wrapper." }
+            ],
+            "returns": [
+                { "name": "contentFrameId", "$ref": "Network.FrameId", "optional": true, "description": "Frame ID for frame owner elements." },
+                { "name": "ownerFrameId", "$ref": "Network.FrameId", "optional": true, "description": "ID of the owning frame element." }
+            ]
+        },
+        {
+          "name": "scrollIntoViewIfNeeded",
+          "description": "Scrolls the given rect into view if not already in the viewport.",
+          "parameters": [
+              { "name": "objectId", "$ref": "Runtime.RemoteObjectId", "description": "JavaScript object id of the node wrapper." },
+              { "name": "rect", "$ref": "Rect", "optional": true, "description": "Rect relative to the node's border box, in CSS pixels." }
+          ]
+        },
+        {
+            "name": "getContentQuads",
+            "description": "Returns quads that describe node position on the page. This method\nmight return multiple quads for inline nodes.",
+            "parameters": [
+                { "name": "objectId", "$ref": "Runtime.RemoteObjectId", "description": "JavaScript object id of the node wrapper." }
+            ],
+            "returns": [
+                {
+                    "name": "quads", "type": "array", "items": { "$ref": "Quad" }, "description": "Quads that describe node layout relative to viewport."
+                }
+            ]
+        },
+        {
+            "name": "setInputFiles",
+            "description": "Sets input files for given <input type=file>",
+            "parameters": [
+                { "name": "objectId", "$ref": "Runtime.RemoteObjectId", "description": "Input element handle." },
+                { "name": "files", "type": "array", "items": { "$ref": "FilePayload" }, "description": "Files to set" }
+            ]
         }
     ],
     "events": [
diff --git a/Source/JavaScriptCore/inspector/protocol/Dialog.json b/Source/JavaScriptCore/inspector/protocol/Dialog.json
new file mode 100644
index 0000000000000000000000000000000000000000..79edea03fed4e9be5da96e1275e182a479cb7a0a
--- /dev/null
+++ b/Source/JavaScriptCore/inspector/protocol/Dialog.json
@@ -0,0 +1,36 @@
+{
+    "domain": "Dialog",
+    "description": "Actions and events related to alert boxes.",
+    "availability": ["web"],
+    "types": [
+    ],
+    "commands": [
+        {
+            "name": "enable",
+            "description": "Enables dialog domain notifications."
+        },
+        {
+            "name": "disable",
+            "description": "Disables dialog domain notifications."
+        },
+        {
+            "name": "handleJavaScriptDialog",
+            "description": "Accepts or dismisses a JavaScript initiated dialog (alert, confirm, prompt, or onbeforeunload).",
+            "parameters": [
+                { "name": "accept", "type": "boolean", "description": "Whether to accept or dismiss the dialog."},
+                { "name": "promptText", "optional": true, "type": "string", "description": "The text to enter into the dialog prompt before accepting. Used only if this is a prompt dialog."}
+            ]
+        }
+    ],
+    "events": [
+        {
+            "name": "javascriptDialogOpening",
+            "description": "Fired when a JavaScript initiated dialog (alert, confirm, prompt, or onbeforeunload) is about to open.",
+            "parameters": [
+                { "name": "type", "type": "string", "description": "Dialog type."},
+                { "name": "message", "type": "string", "description": "Message that will be displayed by the dialog."},
+                { "name": "defaultPrompt", "optional": true, "type": "string", "description": "Default dialog prompt."}
+            ]
+        }
+    ]
+}
diff --git a/Source/JavaScriptCore/inspector/protocol/Emulation.json b/Source/JavaScriptCore/inspector/protocol/Emulation.json
new file mode 100644
index 0000000000000000000000000000000000000000..552e5dd60fa53fada79f8d6e333f52bc10a2bead
--- /dev/null
+++ b/Source/JavaScriptCore/inspector/protocol/Emulation.json
@@ -0,0 +1,39 @@
+{
+    "domain": "Emulation",
+    "availability": ["web"],
+    "commands": [
+        {
+            "name": "setDeviceMetricsOverride",
+            "description": "Overrides device metrics with provided values.",
+            "async": true,
+            "parameters": [
+                { "name": "width", "type": "integer" },
+                { "name": "height", "type": "integer" },
+                { "name": "deviceScaleFactor", "type": "number" },
+                { "name": "fixedLayout", "type": "boolean" }
+            ]
+        },
+        {
+            "name": "setJavaScriptEnabled",
+            "description": "Allows to disable script execution for the page.",
+            "parameters": [
+                { "name": "enabled", "type": "boolean" }
+            ]
+        },
+        {
+            "name": "setAuthCredentials",
+            "description": "Credentials to use during HTTP authentication.",
+            "parameters": [
+                { "name": "username", "type": "string", "optional": true },
+                { "name": "password", "type": "string", "optional": true }
+            ]
+        },
+        {
+            "name": "setActiveAndFocused",
+            "description": "Makes page focused for test.",
+            "parameters": [
+                { "name": "active", "type": "boolean", "optional": true }
+            ]
+        }
+    ]
+}
diff --git a/Source/JavaScriptCore/inspector/protocol/Input.json b/Source/JavaScriptCore/inspector/protocol/Input.json
new file mode 100644
index 0000000000000000000000000000000000000000..34909cce9f6d8d7c74be4c96e40f80cadb2f931d
--- /dev/null
+++ b/Source/JavaScriptCore/inspector/protocol/Input.json
@@ -0,0 +1,165 @@
+{
+    "domain": "Input",
+    "availability": ["web"],
+    "types": [
+        {
+            "id": "TimeSinceEpoch",
+            "description": "UTC time in seconds, counted from January 1, 1970.",
+            "type": "number"
+        }
+    ],
+    "commands": [
+        {
+            "name": "dispatchKeyEvent",
+            "description": "Dispatches a key event to the page.",
+            "async": true,
+            "parameters": [
+                {
+                    "name": "type",
+                    "description": "Type of the key event.",
+                    "type": "string",
+                    "enum": [
+                        "keyDown",
+                        "keyUp"
+                    ]
+                },
+                {
+                    "name": "modifiers",
+                    "description": "Bit field representing pressed modifier keys. (default: 0).",
+                    "optional": true,
+                    "type": "integer"
+                },
+                {
+                    "name": "text",
+                    "description": "Text as generated by processing a virtual key code with a keyboard layout. Not needed for\nfor `keyUp` and `rawKeyDown` events (default: \"\")",
+                    "optional": true,
+                    "type": "string"
+                },
+                {
+                    "name": "unmodifiedText",
+                    "description": "Text that would have been generated by the keyboard if no modifiers were pressed (except for\nshift). Useful for shortcut (accelerator) key handling (default: \"\").",
+                    "optional": true,
+                    "type": "string"
+                },
+                {
+                    "name": "code",
+                    "description": "Unique DOM defined string value for each physical key (e.g., 'KeyA') (default: \"\").",
+                    "optional": true,
+                    "type": "string"
+                },
+                {
+                    "name": "key",
+                    "description": "Unique DOM defined string value describing the meaning of the key in the context of active\nmodifiers, keyboard layout, etc (e.g., 'AltGr') (default: \"\").",
+                    "optional": true,
+                    "type": "string"
+                },
+                {
+                    "name": "windowsVirtualKeyCode",
+                    "description": "Windows virtual key code (default: 0).",
+                    "optional": true,
+                    "type": "integer"
+                },
+                {
+                    "name": "nativeVirtualKeyCode",
+                    "description": "Native virtual key code (default: 0).",
+                    "optional": true,
+                    "type": "integer"
+                },
+                {
+                    "name": "autoRepeat",
+                    "description": "Whether the event was generated from auto repeat (default: false).",
+                    "optional": true,
+                    "type": "boolean"
+                },
+                {
+                    "name": "isKeypad",
+                    "description": "Whether the event was generated from the keypad (default: false).",
+                    "optional": true,
+                    "type": "boolean"
+                },
+                {
+                    "name": "isSystemKey",
+                    "description": "Whether the event was a system key event (default: false).",
+                    "optional": true,
+                    "type": "boolean"
+                },
+                {
+                    "name": "macCommands",
+                    "description": "Mac editing commands associated with this key",
+                    "type": "array",
+                    "optional": true,
+                    "items": {
+                      "type": "string"
+                    }
+                }
+            ]
+        },
+        {
+            "name": "dispatchMouseEvent",
+            "description": "Dispatches a mouse event to the page.",
+            "async": true,
+            "parameters": [
+                {
+                    "name": "type",
+                    "description": "Type of the mouse event.",
+                    "type": "string",
+                    "enum": [ "move", "down", "up", "wheel"]
+                },
+                {
+                    "name": "x",
+                    "description": "X coordinate of the event relative to the main frame's viewport in CSS pixels.",
+                    "type": "integer"
+                },
+                {
+                    "name": "y",
+                    "description": "Y coordinate of the event relative to the main frame's viewport in CSS pixels. 0 refers to\nthe top of the viewport and Y increases as it proceeds towards the bottom of the viewport.",
+                    "type": "integer"
+                },
+                {
+                    "name": "modifiers",
+                    "description": "Bit field representing pressed modifier keys. Alt=1, Ctrl=2, Meta/Command=4, Shift=8\n(default: 0).",
+                    "optional": true,
+                    "type": "integer"
+                },
+                {
+                    "name": "button",
+                    "description": "Mouse button (default: \"none\").",
+                    "optional": true,
+                    "type": "string",
+                    "enum": [
+                        "none",
+                        "left",
+                        "middle",
+                        "right",
+                        "back",
+                        "forward"
+                    ]
+                },
+                {
+                    "name": "buttons",
+                    "description": "A number indicating which buttons are pressed on the mouse when a mouse event is triggered.\nLeft=1, Right=2, Middle=4, Back=8, Forward=16, None=0.",
+                    "optional": true,
+                    "type": "integer"
+                },
+                {
+                    "name": "clickCount",
+                    "description": "Number of times the mouse button was clicked (default: 0).",
+                    "optional": true,
+                    "type": "integer"
+                },
+                {
+                    "name": "deltaX",
+                    "description": "X delta in CSS pixels for mouse wheel event (default: 0).",
+                    "optional": true,
+                    "type": "integer"
+                },
+                {
+                    "name": "deltaY",
+                    "description": "Y delta in CSS pixels for mouse wheel event (default: 0).",
+                    "optional": true,
+                    "type": "integer"
+                }
+            ]
+        }
+    ]
+}
diff --git a/Source/JavaScriptCore/inspector/protocol/Network.json b/Source/JavaScriptCore/inspector/protocol/Network.json
index 777a54166ed6664561b3f8249a6abb4ac59d0480..e738f34f65fa8137a16bf7b66bc237b85b2f5208 100644
--- a/Source/JavaScriptCore/inspector/protocol/Network.json
+++ b/Source/JavaScriptCore/inspector/protocol/Network.json
@@ -231,7 +231,8 @@
             "name": "setInterceptionEnabled",
             "description": "Enable interception of network requests.",
             "parameters": [
-                { "name": "enabled", "type": "boolean" }
+                { "name": "enabled", "type": "boolean" },
+                { "name": "interceptRequests", "type": "boolean", "optional": true }
             ]
         },
         {
@@ -258,7 +259,18 @@
             "name": "interceptContinue",
             "description": "Continue an interception with no modifications.",
             "parameters": [
-                { "name": "requestId", "$ref": "RequestId", "description": "Identifier for the intercepted Network request or response to continue." }
+                { "name": "requestId", "$ref": "RequestId", "description": "Identifier for the intercepted Network request or response to continue." },
+                { "name": "method", "type": "string", "optional": true,"description": "HTTP request method." },
+                { "name": "headers", "$ref": "Headers", "optional": true, "description": "HTTP response headers. Pass through original values if unmodified." },
+                { "name": "postData", "type": "string", "optional": true, "description": "HTTP POST request data." }
+            ]
+        },
+        {
+            "name": "interceptAsError",
+            "description": "Abort the intercepted request with given reason.",
+            "parameters": [
+                { "name": "requestId", "$ref": "RequestId", "description": "Identifier for the intercepted Network request." },
+                { "name": "reason", "type": "string", "description": "Deliver error reason for the request." }
             ]
         },
         {
@@ -266,13 +278,20 @@
             "description": "Provide response content for an intercepted response.",
             "parameters": [
                 { "name": "requestId", "$ref": "RequestId", "description": "Identifier for the intercepted Network response to modify." },
-                { "name": "content", "type": "string" },
-                { "name": "base64Encoded", "type": "boolean", "description": "True, if content was sent as base64." },
+                { "name": "content", "type": "string", "optional": true },
+                { "name": "base64Encoded", "type": "boolean", "optional": true, "description": "True, if content was sent as base64." },
                 { "name": "mimeType", "type": "string", "optional": true, "description": "MIME Type for the data." },
                 { "name": "status", "type": "integer", "optional": true, "description": "HTTP response status code. Pass through original values if unmodified." },
                 { "name": "statusText", "type": "string", "optional": true, "description": "HTTP response status text. Pass through original values if unmodified." },
                 { "name": "headers", "$ref": "Headers", "optional": true, "description": "HTTP response headers. Pass through original values if unmodified." }
             ]
+        },
+        {
+            "name": "setEmulateOfflineState",
+            "description": "Emulate offline state overriding the actual state.",
+            "parameters": [
+                { "name": "offline", "type": "boolean", "description": "True to emulate offline." }
+            ]
         }
     ],
     "events": [
@@ -356,6 +375,14 @@
                 { "name": "response", "$ref": "Response", "description": "Original response content that would proceed if this is continued." }
             ]
         },
+        {
+            "name": "requestIntercepted",
+            "description": "Fired when HTTP request has been intercepted. The frontend must response with <code>Network.interceptContinue</code> or <code>Network.interceptWithRespons</code>` to continue this response.",
+            "parameters": [
+                { "name": "requestId", "$ref": "RequestId", "description": "Identifier for this intercepted network. Corresponds with an earlier <code>Network.requestWillBeSent</code>." },
+                { "name": "request", "$ref": "Request", "description": "Original request content that would proceed if this is continued." }
+            ]
+        },
         {
             "name": "webSocketWillSendHandshakeRequest",
             "description": "Fired when WebSocket is about to initiate handshake.",
diff --git a/Source/JavaScriptCore/inspector/protocol/Page.json b/Source/JavaScriptCore/inspector/protocol/Page.json
index a8fc5332ac92424b00a3dec62152fd3c5f28544e..6aa07fd2ee4e0dff43b151d1cee7497f4aa0505b 100644
--- a/Source/JavaScriptCore/inspector/protocol/Page.json
+++ b/Source/JavaScriptCore/inspector/protocol/Page.json
@@ -110,6 +110,41 @@
                 { "name": "session", "type": "boolean", "description": "True in case of session cookie." },
                 { "name": "sameSite", "$ref": "CookieSameSitePolicy", "description": "Cookie Same-Site policy." }
             ]
+        },
+        {
+            "id": "AXNode",
+            "type": "object",
+            "description": "Accessibility Node",
+            "properties": [
+                { "name": "role", "type": "string", "description": "The role."},
+                { "name": "name", "type": "string","optional": true, "description": "A human readable name for the node."},
+                { "name": "value", "type": "any", "optional": true, "description": "The current value of the node."},
+                { "name": "description", "type": "string", "optional": true, "description": "An additional human readable description of the node."},
+                { "name": "keyshortcuts", "type": "string", "optional": true, "description": "Keyboard shortcuts associated with this node."},
+                { "name": "roledescription", "type": "string", "optional": true, "description": "A human readable alternative to the role."},
+                { "name": "valuetext", "type": "string", "optional": true, "description": "A description of the current value."},
+                { "name": "disabled", "type": "boolean", "optional": true, "description": "Whether the node is disabled."},
+                { "name": "expanded", "type": "boolean", "optional": true, "description": "Whether the node is expanded or collapsed."},
+                { "name": "focused", "type": "boolean", "optional": true, "description": "Whether the node is focused."},
+                { "name": "modal", "type": "boolean", "optional": true, "description": "Whether the node is modal."},
+                { "name": "multiline", "type": "boolean", "optional": true, "description": "Whether the node text input supports multiline."},
+                { "name": "multiselectable", "type": "boolean", "optional": true, "description": "Whether more than one child can be selected."},
+                { "name": "readonly", "type": "boolean", "optional": true, "description": "Whether the node is read only."},
+                { "name": "required", "type": "boolean", "optional": true, "description": "Whether the node is required."},
+                { "name": "selected", "type": "boolean", "optional": true, "description": "Whether the node is selected in its parent node."},
+                { "name": "checked", "type": "string", "optional": true, "enum": ["true", "false", "mixed"], "description": "Whether the checkbox is checked, or \"mixed\"."},
+                { "name": "pressed", "type": "string", "optional": true, "enum": ["true", "false", "mixed"], "description": "Whether the toggle button is checked, or \"mixed\"."},
+                { "name": "level", "type": "integer", "optional": true, "description": "The level of a heading."},
+                { "name": "valuemin", "type": "number", "optional": true, "description": "The minimum value in a node."},
+                { "name": "valuemax", "type": "number", "optional": true, "description": "The maximum value in a node."},
+                { "name": "autocomplete", "type": "string", "optional": true, "description": "What kind of autocomplete is supported by a control."},
+                { "name": "haspopup", "type": "string", "optional": true, "description": "What kind of popup is currently being shown for a node."},
+                { "name": "invalid", "type": "string", "optional": true, "enum": ["true", "false", "grammar", "spelling"], "description": "Whether and in what way this node's value is invalid."},
+                { "name": "orientation", "type": "string", "optional": true, "description": "Whether the node is oriented horizontally or vertically."},
+                { "name": "focusable", "type": "boolean", "optional": true, "description": "Whether the node is focusable."},
+                { "name": "children", "type": "array", "optional": true, "items": { "$ref": "AXNode"}, "description": "Child AXNodes of this node, if any."},
+                { "name": "found", "type": "boolean", "optional": true, "description": "True if this AXNode corresponds with the ObjectId passed into acessibilitySnapshot."}
+            ]
         }
     ],
     "commands": [
@@ -129,11 +164,21 @@
                 { "name": "revalidateAllResources", "type": "boolean", "optional": true, "description": "If true, all cached subresources will be revalidated when the main resource loads. Otherwise, only expired cached subresources will be revalidated (the default behavior for most WebKit clients)." }
             ]
         },
+        {
+            "name": "goBack",
+            "description": "Goes back in the history."
+        },
+        {
+            "name": "goForward",
+            "description": "Goes forward in the history."
+        },
         {
             "name": "navigate",
             "description": "Navigates current page to the given URL.",
             "parameters": [
-                { "name": "url", "type": "string", "description": "URL to navigate the page to." }
+                { "name": "url", "type": "string", "description": "URL to navigate the page to." },
+                { "name": "frameId", "$ref": "Network.FrameId", "optional": true, "description": "Id of the frame to navigate."},
+                { "name": "referrer", "type": "string", "optional": true, "description": "Referrer URL." }
             ]
         },
         {
@@ -246,6 +291,20 @@
                 { "name": "appearance", "$ref": "Appearance", "description": "Appearance name to force. Empty string disables the override." }
             ]
         },
+        {
+            "name": "setTimeZone",
+            "description": "Enables time zone emulation.",
+            "parameters": [
+                { "name": "timeZone", "type": "string", "optional": true }
+            ]
+        },
+        {
+            "name": "setTouchEmulationEnabled",
+            "description": "Enables touch events on platforms that lack them.",
+            "parameters": [
+                {"name": "enabled", "type": "boolean", "description": "Whether touch should be enabled."}
+            ]
+        },
         {
             "name": "snapshotNode",
             "description": "Capture a snapshot of the specified node that does not include unrelated layers.",
@@ -276,19 +335,78 @@
             "returns": [
                 { "name": "data", "type": "string", "description": "Base64-encoded web archive." }
             ]
+        },
+        {
+            "name": "insertText",
+            "description": "Insert text into the current selection of the page.",
+            "parameters": [
+                { "name": "text", "type": "string", "description": "Text to insert." }
+            ]
+        },
+        {
+            "name": "accessibilitySnapshot",
+            "description": "Serializes and returns all of the accessibility nodes of the page.",
+            "parameters": [
+                { "name": "objectId", "type": "string", "optional": true, "description": "Object Id of a node to find in the accessibility tree."}
+            ],
+            "returns": [
+                { "name": "axNode", "$ref": "AXNode", "description": "The root AXNode."}
+            ]
+        },
+        {
+            "name": "setInterceptFileChooserDialog",
+            "description": "Intercepts file chooser dialog",
+            "parameters": [
+                { "name": "enabled", "type": "boolean", "description": "True to enable." }
+            ]
+        },
+        {
+            "name": "setDefaultBackgroundColorOverride",
+            "description": "Sets or clears an override of the default background color of the frame. This override is used if the content does not specify one.",
+            "parameters": [
+                { "name": "color", "$ref": "DOM.RGBAColor", "optional": true, "description": "RGBA of the default background color. If not specified, any existing override will be cleared." }
+            ]
+        },
+        {
+            "name": "createUserWorld",
+            "description": "Creates an user world for every loaded frame.",
+            "parameters": [
+                { "name": "name", "type": "string", "description": "Isolated world name, will be used as an execution context name." }
+            ]
+        },
+        {
+            "name": "setBypassCSP",
+            "description": "Enable page Content Security Policy by-passing.",
+            "parameters": [
+                { "name": "enabled", "type": "boolean", "description": "Whether to bypass page CSP." }
+            ]
+        },
+        {
+            "name": "crash",
+            "description": "Crashes the page process"
+        },
+        {
+            "name": "setScreenSizeOverride",
+            "description": "Overrides screen size with provided values.",
+            "parameters": [
+                { "name": "width", "type": "integer" },
+                { "name": "height", "type": "integer" }
+            ]
         }
     ],
     "events": [
         {
             "name": "domContentEventFired",
             "parameters": [
-                { "name": "timestamp", "type": "number" }
+                { "name": "timestamp", "type": "number" },
+                { "name": "frameId", "$ref": "Network.FrameId", "description": "Id of the frame that has fired DOMContentLoaded event." }
             ]
         },
         {
             "name": "loadEventFired",
             "parameters": [
-                { "name": "timestamp", "type": "number" }
+              { "name": "timestamp", "type": "number" },
+              { "name": "frameId", "$ref": "Network.FrameId", "description": "Id of the frame that has fired load event." }
             ]
         },
         {
@@ -298,6 +416,14 @@
                 { "name": "frame", "$ref": "Frame", "description": "Frame object." }
             ]
         },
+        {
+          "name": "frameAttached",
+          "description": "Fired when frame has been attached to its parent.",
+          "parameters": [
+              { "name": "frameId", "$ref": "Network.FrameId", "description": "Id of the frame that has been detached." },
+              { "name": "parentFrameId", "$ref": "Network.FrameId", "optional": true, "description": "Parent frame id if non-root." }
+          ]
+        },
         {
             "name": "frameDetached",
             "description": "Fired when frame has been detached from its parent.",
@@ -334,12 +460,36 @@
                 { "name": "frameId", "$ref": "Network.FrameId", "description": "Id of the frame that has cleared its scheduled navigation." }
             ]
         },
+        {
+            "name": "navigatedWithinDocument",
+            "description": "Fired when same-document navigation happens, e.g. due to history API usage or anchor navigation.",
+            "parameters": [
+                {
+                    "name": "frameId",
+                    "description": "Id of the frame.",
+                    "$ref": "Network.FrameId"
+                },
+                {
+                    "name": "url",
+                    "description": "Frame's new url.",
+                    "type": "string"
+                }
+            ]
+        },
         {
             "name": "defaultAppearanceDidChange",
             "description": "Fired when page's default appearance changes, even if there is a forced appearance.",
             "parameters": [
                 { "name": "appearance", "$ref": "Appearance", "description": "Name of the appearance that is active (not considering any forced appearance.)" }
             ]
+        },
+        {
+            "name": "fileChooserOpened",
+            "description": "Fired when the page shows file chooser for it's <input type=file>.",
+            "parameters": [
+                { "name": "frameId", "$ref": "Network.FrameId", "description": "Frame where file chooser is opened." },
+                { "name": "element", "$ref": "Runtime.RemoteObject", "description": "Input element." }
+            ]
         }
     ]
 }
diff --git a/Source/JavaScriptCore/inspector/protocol/Target.json b/Source/JavaScriptCore/inspector/protocol/Target.json
index 52920cded24a9c6b0ef6fb4e518664955db4f9fa..bbbabc4e7259088b9404e8cc07eecd6f45077da0 100644
--- a/Source/JavaScriptCore/inspector/protocol/Target.json
+++ b/Source/JavaScriptCore/inspector/protocol/Target.json
@@ -10,7 +10,7 @@
             "properties": [
                 { "name": "targetId", "type": "string", "description": "Unique identifier for the target." },
                 { "name": "type", "type": "string", "enum": ["page", "service-worker", "worker"] },
-                { "name": "isProvisional", "type": "boolean", "optional": true, "description": "Whether this is a provisional page target." },
+                { "name": "isProvisional", "type": "boolean", "optional": true, "description": "True value indicates that this is a provisional page target i.e. Such target may be created when current page starts cross-origin navigation. Eventually each provisional target is either committed and swaps with the current target or gets destroyed, e.g. in case of load request failure." },
                 { "name": "isPaused", "type": "boolean", "optional": true, "description": "Whether the target is paused on start and has to be explicitely resumed by inspector." }
             ]
         }
@@ -37,6 +37,21 @@
                 { "name": "targetId", "type": "string" },
                 { "name": "message", "type": "string", "description": "JSON Inspector Protocol message (command) to be dispatched on the backend." }
             ]
+        },
+        {
+            "name": "activate",
+            "description": "Reveals the target on screen.",
+            "parameters": [
+                { "name": "targetId", "type": "string" }
+            ]
+        },
+        {
+            "name": "close",
+            "description": "Closes the target.",
+            "parameters": [
+                { "name": "targetId", "type": "string" },
+                { "name": "runBeforeUnload", "type": "boolean", "optional": true }
+            ]
         }
     ],
     "events": [
@@ -49,7 +64,8 @@
         {
             "name": "targetDestroyed",
             "parameters": [
-                { "name": "targetId", "type": "string" }
+                { "name": "targetId", "type": "string" },
+                { "name": "crashed", "type": "boolean" }
             ]
         },
         {
diff --git a/Source/JavaScriptCore/inspector/protocol/Worker.json b/Source/JavaScriptCore/inspector/protocol/Worker.json
index 9e2bee913d37c79fedbb918176a43022b84fa45b..ad8926d773144114dad3842fa0fe239155a15d9e 100644
--- a/Source/JavaScriptCore/inspector/protocol/Worker.json
+++ b/Source/JavaScriptCore/inspector/protocol/Worker.json
@@ -16,7 +16,7 @@
             "description": "Sent after the frontend has sent all initialization messages and can resume this worker. This command is required to allow execution in the worker.",
             "parameters": [
                 { "name": "workerId", "type": "string" }
-            ]            
+            ]
         },
         {
             "name": "sendMessageToWorker",
@@ -32,7 +32,8 @@
             "name": "workerCreated",
             "parameters": [
                 { "name": "workerId", "type": "string" },
-                { "name": "url", "type": "string" }
+                { "name": "url", "type": "string" },
+                { "name": "frameId", "$ref": "Network.FrameId", "description": "Id of the frame this worker belongs to." }
             ]
         },
         {
diff --git a/Source/JavaScriptCore/runtime/DateConversion.cpp b/Source/JavaScriptCore/runtime/DateConversion.cpp
index 955756ba405f400970610f9a68c7ed42a67cb015..1520c0a1475a90de2795e4ccd8919c1bb1384066 100644
--- a/Source/JavaScriptCore/runtime/DateConversion.cpp
+++ b/Source/JavaScriptCore/runtime/DateConversion.cpp
@@ -100,17 +100,23 @@ String formatDateTime(const GregorianDateTime& t, DateTimeFormat format, bool as
             appendNumber<2>(builder, offset / 60);
             appendNumber<2>(builder, offset % 60);
 
-#if OS(WINDOWS)
-            TIME_ZONE_INFORMATION timeZoneInformation;
-            GetTimeZoneInformation(&timeZoneInformation);
-            const WCHAR* winTimeZoneName = t.isDST() ? timeZoneInformation.DaylightName : timeZoneInformation.StandardName;
-            String timeZoneName(winTimeZoneName);
+            String timeZoneName;
+            if (!WTF::timeZoneDisplayNameForAutomation().isEmpty()) {
+                timeZoneName = WTF::timeZoneDisplayNameForAutomation();
+            } else {
+ #if OS(WINDOWS)
+                TIME_ZONE_INFORMATION timeZoneInformation;
+                GetTimeZoneInformation(&timeZoneInformation);
+                const WCHAR* winTimeZoneName = t.isDST() ? timeZoneInformation.DaylightName : timeZoneInformation.StandardName;
+                timeZoneName = String(winTimeZoneName);
 #else
-            struct tm gtm = t;
-            char timeZoneName[70];
-            strftime(timeZoneName, sizeof(timeZoneName), "%Z", &gtm);
+                struct tm gtm = t;
+                char tzName[70];
+                strftime(tzName, sizeof(tzName), "%Z", &gtm);
+                timeZoneName = String(tzName);
 #endif
-            if (timeZoneName[0]) {
+            }
+            if (!timeZoneName.isEmpty()) {
                 builder.appendLiteral(" (");
                 builder.append(timeZoneName);
                 builder.append(')');
diff --git a/Source/JavaScriptCore/runtime/IntlDateTimeFormat.cpp b/Source/JavaScriptCore/runtime/IntlDateTimeFormat.cpp
index 9817a45ea2f3a22844ed3e56816cff94eb051423..67f7459a556ed22740fbfcd2b1b7b530d34d5bb5 100644
--- a/Source/JavaScriptCore/runtime/IntlDateTimeFormat.cpp
+++ b/Source/JavaScriptCore/runtime/IntlDateTimeFormat.cpp
@@ -39,6 +39,7 @@
 #include <unicode/ucal.h>
 #include <unicode/udatpg.h>
 #include <unicode/uenum.h>
+#include <wtf/DateMath.h>
 #include <wtf/text/StringBuilder.h>
 
 #if JSC_ICU_HAS_UFIELDPOSITER
@@ -113,6 +114,10 @@ void IntlDateTimeFormat::setBoundFormat(VM& vm, JSBoundFunction* format)
 
 static String defaultTimeZone()
 {
+    String tz = WTF::timeZoneForAutomation();
+    if (!tz.isEmpty())
+        return tz;
+
     // 6.4.3 DefaultTimeZone () (ECMA-402 2.0)
     // The DefaultTimeZone abstract operation returns a String value representing the valid (6.4.1) and canonicalized (6.4.2) time zone name for the host environment’s current time zone.
 
diff --git a/Source/WTF/wtf/DateMath.cpp b/Source/WTF/wtf/DateMath.cpp
index 1999737341553001d5246b8190e9ea11d615a158..540ed892bca8110f8013477da7bd9b459a17e60d 100644
--- a/Source/WTF/wtf/DateMath.cpp
+++ b/Source/WTF/wtf/DateMath.cpp
@@ -77,11 +77,16 @@
 #include <limits>
 #include <stdint.h>
 #include <time.h>
+#include <unicode/ucal.h>
 #include <wtf/Assertions.h>
 #include <wtf/ASCIICType.h>
+#include <wtf/Language.h>
 #include <wtf/MathExtras.h>
+#include <wtf/NeverDestroyed.h>
 #include <wtf/StdLibExtras.h>
+#include <wtf/ThreadSpecific.h>
 #include <wtf/text/StringBuilder.h>
+#include <wtf/unicode/UTF8Conversion.h>
 
 #if OS(WINDOWS)
 #include <windows.h>
@@ -107,6 +112,18 @@ template<unsigned length> inline bool startsWithLettersIgnoringASCIICase(const c
     return equalLettersIgnoringASCIICase(string, lowercaseLetters, length - 1);
 }
 
+struct TimeZoneForAutomation {
+    UCalendar* cal;
+    String id;
+    String displayName;
+};
+
+static TimeZoneForAutomation& innerTimeZoneForAutomation()
+{
+    static NeverDestroyed<WTF::ThreadSpecific<TimeZoneForAutomation>> timeZoneForAutomation;
+    return *timeZoneForAutomation.get();
+}
+
 /* Constants */
 
 const char* const weekdayName[7] = { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };
@@ -333,6 +350,14 @@ static double calculateDSTOffset(time_t localTime, double utcOffset)
 // Returns combined offset in millisecond (UTC + DST).
 LocalTimeOffset calculateLocalTimeOffset(double ms, TimeType inputTimeType)
 {
+    TimeZoneForAutomation& tz = innerTimeZoneForAutomation();
+    if (tz.cal) {
+        UErrorCode status = U_ZERO_ERROR;
+        ucal_setMillis(tz.cal, ms, &status);
+        int32_t offset = ucal_get(tz.cal, UCAL_ZONE_OFFSET, &status);
+        int32_t dstOffset = ucal_get(tz.cal, UCAL_DST_OFFSET, &status);
+        return LocalTimeOffset(dstOffset, offset + dstOffset);
+    }
 #if HAVE(TM_GMTOFF)
     double localToUTCTimeOffset = inputTimeType == LocalTime ? calculateUTCOffset() : 0;
 #else
@@ -1034,4 +1059,65 @@ String makeRFC2822DateString(unsigned dayOfWeek, unsigned day, unsigned month, u
     return stringBuilder.toString();
 }
 
+bool setTimeZoneForAutomation(const String& timeZone)
+{
+    innerTimeZoneForAutomation().displayName = String();
+    if (innerTimeZoneForAutomation().cal) {
+        ucal_close(innerTimeZoneForAutomation().cal);
+        innerTimeZoneForAutomation().cal = nullptr;
+    }
+    if (timeZone.isEmpty()) {
+        innerTimeZoneForAutomation().id = String();
+        return true;
+    }
+
+    // Timezone is ascii.
+    Vector<UChar> buffer(timeZone.length());
+    UChar* bufferStart = buffer.data();
+    CString ctz = timeZone.utf8();
+    if (!Unicode::convertUTF8ToUTF16(ctz.data(), ctz.data() + ctz.length(), &bufferStart, bufferStart + timeZone.length()))
+        return false;
+
+    Vector<UChar, 32> canonicalBuffer(32);
+    UErrorCode status = U_ZERO_ERROR;
+    auto canonicalLength = ucal_getCanonicalTimeZoneID(buffer.data(), buffer.size(), canonicalBuffer.data(), canonicalBuffer.size(), nullptr, &status);
+    if (status == U_BUFFER_OVERFLOW_ERROR) {
+        status = U_ZERO_ERROR;
+        canonicalBuffer.grow(canonicalLength);
+        ucal_getCanonicalTimeZoneID(buffer.data(), buffer.size(), canonicalBuffer.data(), canonicalLength, nullptr, &status);
+    }
+    if (!U_SUCCESS(status))
+        return false;
+
+    UCalendar* cal = ucal_open(canonicalBuffer.data(), canonicalLength, nullptr, UCAL_TRADITIONAL, &status);
+    if (!U_SUCCESS(status))
+        return false;
+
+    Vector<UChar, 32> displayNameBuffer(32);
+    auto displayNameLength = ucal_getTimeZoneDisplayName(cal, UCAL_STANDARD, defaultLanguage().utf8().data(), displayNameBuffer.data(), displayNameBuffer.size(), &status);
+    if (status == U_BUFFER_OVERFLOW_ERROR) {
+        status = U_ZERO_ERROR;
+        displayNameBuffer.grow(displayNameLength);
+        ucal_getTimeZoneDisplayName(cal, UCAL_STANDARD, defaultLanguage().utf8().data(), displayNameBuffer.data(), displayNameLength, &status);
+    }
+    if (!U_SUCCESS(status))
+        return false;
+
+    TimeZoneForAutomation& tzfa = innerTimeZoneForAutomation();
+    tzfa.cal = cal;
+    tzfa.id = String(canonicalBuffer.data(), canonicalLength);
+    tzfa.displayName = String(displayNameBuffer.data(), displayNameLength);
+    return true;
+}
+
+String timeZoneForAutomation()
+{
+    return innerTimeZoneForAutomation().id;
+}
+
+String timeZoneDisplayNameForAutomation()
+{
+    return innerTimeZoneForAutomation().displayName;
+}
+
 } // namespace WTF
diff --git a/Source/WTF/wtf/DateMath.h b/Source/WTF/wtf/DateMath.h
index 602f89a49d454cc5e5acd030024227d49d98c61f..41811e65bd0f15b443fb90d37ee4d0a21780a518 100644
--- a/Source/WTF/wtf/DateMath.h
+++ b/Source/WTF/wtf/DateMath.h
@@ -389,6 +389,10 @@ inline int dayInMonthFromDayInYear(int dayInYear, bool leapYear)
     return d - step;
 }
 
+WTF_EXPORT_PRIVATE bool setTimeZoneForAutomation(const String& timeZone);
+WTF_EXPORT_PRIVATE String timeZoneForAutomation();
+WTF_EXPORT_PRIVATE String timeZoneDisplayNameForAutomation();
+
 // Returns combined offset in millisecond (UTC + DST).
 WTF_EXPORT_PRIVATE LocalTimeOffset calculateLocalTimeOffset(double utcInMilliseconds, TimeType = UTCTime);
 
diff --git a/Source/WTF/wtf/PlatformHave.h b/Source/WTF/wtf/PlatformHave.h
index d060be5be35f6079f1c8874860bda35f8c38cb11..c16a3eccfa080e24a50e1e2f15a836d628932dc8 100644
--- a/Source/WTF/wtf/PlatformHave.h
+++ b/Source/WTF/wtf/PlatformHave.h
@@ -379,7 +379,7 @@
 #define HAVE_NSHTTPCOOKIESTORAGE__INITWITHIDENTIFIER_WITH_INACCURATE_NULLABILITY 1
 #endif
 
-#if (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101400) || PLATFORM(IOS) || PLATFORM(MACCATALYST)
+#if (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101400) || PLATFORM(IOS) || PLATFORM(MACCATALYST) || PLATFORM(GTK) || PLATFORM(WPE) || PLATFORM(WIN)
 #define HAVE_OS_DARK_MODE_SUPPORT 1
 #endif
 
diff --git a/Source/WebCore/Modules/geolocation/Geolocation.cpp b/Source/WebCore/Modules/geolocation/Geolocation.cpp
index 6d5be9a591a272cd67d6e9d097b30505bdf8ae5e..8f67ba28c380e844c8e4191ee704466559d88f97 100644
--- a/Source/WebCore/Modules/geolocation/Geolocation.cpp
+++ b/Source/WebCore/Modules/geolocation/Geolocation.cpp
@@ -356,8 +356,9 @@ bool Geolocation::shouldBlockGeolocationRequests()
     bool isSecure = SecurityOrigin::isSecure(document()->url());
     bool hasMixedContent = !document()->foundMixedContent().isEmpty();
     bool isLocalOrigin = securityOrigin()->isLocal();
+    bool isPotentiallyTrustworthy = securityOrigin()->isPotentiallyTrustworthy();
     if (securityOrigin()->canRequestGeolocation()) {
-        if (isLocalOrigin || (isSecure && !hasMixedContent) || isRequestFromIBooks())
+        if (isLocalOrigin || isPotentiallyTrustworthy || (isSecure && !hasMixedContent) || isRequestFromIBooks())
             return false;
     }
     
diff --git a/Source/WebCore/SourcesCocoa.txt b/Source/WebCore/SourcesCocoa.txt
index 4a092d88ff8ec02c38c29889974ec9a29ca30d3b..a95d3ccd9a75e1ab8791abf9fe96a368b52dc967 100644
--- a/Source/WebCore/SourcesCocoa.txt
+++ b/Source/WebCore/SourcesCocoa.txt
@@ -647,7 +647,7 @@ WHLSLStandardLibraryFunctionMap.cpp
 
 #endif
 
-#if ENABLE_IOS_TOUCH_EVENTS
+#if ENABLE_TOUCH_EVENTS
 
     JSTouch.cpp
     JSTouchEvent.cpp
diff --git a/Source/WebCore/WebCore.order b/Source/WebCore/WebCore.order
index 34f1a72596fb89c8b647fff3348cca3d959c014c..ab6e42c4da2a8a77f66ce532a3a12bb9ee991207 100644
--- a/Source/WebCore/WebCore.order
+++ b/Source/WebCore/WebCore.order
@@ -3094,7 +3094,6 @@ __ZN7WebCore14DocumentLoader23stopLoadingSubresourcesEv
 __ZN7WebCore14DocumentLoader18stopLoadingPlugInsEv
 __ZN7WebCore14DocumentLoader15detachFromFrameEv
 __ZN7WebCore20ApplicationCacheHost22setDOMApplicationCacheEPNS_19DOMApplicationCacheE
-__ZN7WebCore24InspectorInstrumentation27loaderDetachedFromFrameImplEPNS_19InstrumentingAgentsEPNS_14DocumentLoaderE
 __ZN7WebCore14DocumentLoaderD0Ev
 __ZN7WebCore14DocumentLoaderD2Ev
 __ZN7WebCore14DocumentLoader17clearMainResourceEv
diff --git a/Source/WebCore/WebCore.xcodeproj/project.pbxproj b/Source/WebCore/WebCore.xcodeproj/project.pbxproj
index ddba948c2a08f4a3789773c7ce6c1c1f16d5f11e..c8399e021f1975ada36a7c07de295e1b94305862 100644
--- a/Source/WebCore/WebCore.xcodeproj/project.pbxproj
+++ b/Source/WebCore/WebCore.xcodeproj/project.pbxproj
@@ -4934,6 +4934,14 @@
 		EDE3A5000C7A430600956A37 /* ColorMac.h in Headers */ = {isa = PBXBuildFile; fileRef = EDE3A4FF0C7A430600956A37 /* ColorMac.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		EDEC98030AED7E170059137F /* WebCorePrefix.h in Headers */ = {isa = PBXBuildFile; fileRef = EDEC98020AED7E170059137F /* WebCorePrefix.h */; };
 		EFCC6C8F20FE914400A2321B /* CanvasActivityRecord.h in Headers */ = {isa = PBXBuildFile; fileRef = EFCC6C8D20FE914000A2321B /* CanvasActivityRecord.h */; settings = {ATTRIBUTES = (Private, ); }; };
+		F050E16823AC9C080011CE47 /* PlatformTouchEvent.h in Headers */ = {isa = PBXBuildFile; fileRef = F050E16623AC9C070011CE47 /* PlatformTouchEvent.h */; settings = {ATTRIBUTES = (Private, ); }; };
+		F050E16A23AD660C0011CE47 /* Touch.cpp in Sources */ = {isa = PBXBuildFile; fileRef = F050E16923AD660C0011CE47 /* Touch.cpp */; };
+		F050E16D23AD66630011CE47 /* TouchList.h in Headers */ = {isa = PBXBuildFile; fileRef = F050E16B23AD66620011CE47 /* TouchList.h */; settings = {ATTRIBUTES = (Private, ); }; };
+		F050E16E23AD66630011CE47 /* TouchList.cpp in Sources */ = {isa = PBXBuildFile; fileRef = F050E16C23AD66630011CE47 /* TouchList.cpp */; };
+		F050E17123AD669F0011CE47 /* TouchEvent.cpp in Sources */ = {isa = PBXBuildFile; fileRef = F050E16F23AD669E0011CE47 /* TouchEvent.cpp */; };
+		F050E17223AD669F0011CE47 /* TouchEvent.h in Headers */ = {isa = PBXBuildFile; fileRef = F050E17023AD669F0011CE47 /* TouchEvent.h */; settings = {ATTRIBUTES = (Private, ); }; };
+		F050E17423AD6A800011CE47 /* DocumentTouch.cpp in Sources */ = {isa = PBXBuildFile; fileRef = F050E17323AD6A800011CE47 /* DocumentTouch.cpp */; };
+		F050E17823AD70C50011CE47 /* PlatformTouchPoint.h in Headers */ = {isa = PBXBuildFile; fileRef = F050E17623AD70C40011CE47 /* PlatformTouchPoint.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		F12171F516A8CED2000053CA /* WebVTTElement.cpp in Sources */ = {isa = PBXBuildFile; fileRef = F12171F316A8BC63000053CA /* WebVTTElement.cpp */; };
 		F12171F616A8CF0B000053CA /* WebVTTElement.h in Headers */ = {isa = PBXBuildFile; fileRef = F12171F416A8BC63000053CA /* WebVTTElement.h */; };
 		F32BDCD92363AACA0073B6AE /* UserGestureEmulationScope.h in Headers */ = {isa = PBXBuildFile; fileRef = F32BDCD72363AACA0073B6AE /* UserGestureEmulationScope.h */; };
@@ -15393,6 +15401,14 @@
 		EDEC98020AED7E170059137F /* WebCorePrefix.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; path = WebCorePrefix.h; sourceTree = "<group>"; tabWidth = 4; usesTabs = 0; };
 		EFB7287B2124C73D005C2558 /* CanvasActivityRecord.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = CanvasActivityRecord.cpp; sourceTree = "<group>"; };
 		EFCC6C8D20FE914000A2321B /* CanvasActivityRecord.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = CanvasActivityRecord.h; sourceTree = "<group>"; };
+		F050E16623AC9C070011CE47 /* PlatformTouchEvent.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = PlatformTouchEvent.h; sourceTree = "<group>"; };
+		F050E16923AD660C0011CE47 /* Touch.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = Touch.cpp; path = dom/Touch.cpp; sourceTree = SOURCE_ROOT; };
+		F050E16B23AD66620011CE47 /* TouchList.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = TouchList.h; path = dom/TouchList.h; sourceTree = SOURCE_ROOT; };
+		F050E16C23AD66630011CE47 /* TouchList.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = TouchList.cpp; path = dom/TouchList.cpp; sourceTree = SOURCE_ROOT; };
+		F050E16F23AD669E0011CE47 /* TouchEvent.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = TouchEvent.cpp; path = dom/TouchEvent.cpp; sourceTree = SOURCE_ROOT; };
+		F050E17023AD669F0011CE47 /* TouchEvent.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = TouchEvent.h; path = dom/TouchEvent.h; sourceTree = SOURCE_ROOT; };
+		F050E17323AD6A800011CE47 /* DocumentTouch.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = DocumentTouch.cpp; sourceTree = "<group>"; };
+		F050E17623AD70C40011CE47 /* PlatformTouchPoint.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = PlatformTouchPoint.h; sourceTree = "<group>"; };
 		F12171F316A8BC63000053CA /* WebVTTElement.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = WebVTTElement.cpp; sourceTree = "<group>"; };
 		F12171F416A8BC63000053CA /* WebVTTElement.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WebVTTElement.h; sourceTree = "<group>"; };
 		F32BDCD52363AAC90073B6AE /* UserGestureEmulationScope.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = UserGestureEmulationScope.cpp; sourceTree = "<group>"; };
@@ -20625,7 +20641,12 @@
 				2D2E34A921A4E191004598B5 /* EditableImageReference.h */,
 				1AF326770D78B9440068F0C4 /* EditorClient.h */,
 				93C09A800B064F00005ABD4D /* EventHandler.cpp */,
+				F050E16F23AD669E0011CE47 /* TouchEvent.cpp */,
+				F050E17023AD669F0011CE47 /* TouchEvent.h */,
 				93C09A520B064DB3005ABD4D /* EventHandler.h */,
+				F050E16923AD660C0011CE47 /* Touch.cpp */,
+				F050E16C23AD66630011CE47 /* TouchList.cpp */,
+				F050E16B23AD66620011CE47 /* TouchList.h */,
 				E0FEF371B27C53EAC1C1FBEE /* EventSource.cpp */,
 				E0FEF371B17C53EAC1C1FBEE /* EventSource.h */,
 				E0FEF371B07C53EAC1C1FBEE /* EventSource.idl */,
@@ -25855,7 +25876,9 @@
 				1A2E6E560CC551E0004A2062 /* sql */,
 				B2C3D9EC0D006C1D00EF6F26 /* text */,
 				DFDB912CF8E88A6DA1AD264F /* AbortableTaskQueue.h */,
+				F050E16623AC9C070011CE47 /* PlatformTouchEvent.h */,
 				49AE2D94134EE5F90072920A /* CalculationValue.cpp */,
+				F050E17623AD70C40011CE47 /* PlatformTouchPoint.h */,
 				49AE2D95134EE5F90072920A /* CalculationValue.h */,
 				C330A22113EC196B0000B45B /* ColorChooser.h */,
 				C37CDEBC149EF2030042090D /* ColorChooserClient.h */,
@@ -28075,6 +28098,7 @@
 				BCCFBAE70B5152ED0001F1D7 /* DocumentParser.h */,
 				AD6E71AA1668899D00320C13 /* DocumentSharedObjectPool.cpp */,
 				AD6E71AB1668899D00320C13 /* DocumentSharedObjectPool.h */,
+				F050E17323AD6A800011CE47 /* DocumentTouch.cpp */,
 				6BDB5DC1227BD3B800919770 /* DocumentStorageAccess.cpp */,
 				6BDB5DC0227BD3B800919770 /* DocumentStorageAccess.h */,
 				6BDB5DC5227CA0EB00919770 /* DocumentStorageAccess.idl */,
@@ -28956,6 +28980,7 @@
 				93C4F6EB1108F9A50099D0DB /* AccessibilityScrollbar.h in Headers */,
 				29489FC712C00F0300D83F0F /* AccessibilityScrollView.h in Headers */,
 				0709FC4E1025DEE30059CDBA /* AccessibilitySlider.h in Headers */,
+				F050E16D23AD66630011CE47 /* TouchList.h in Headers */,
 				29D7BCFA1444AF7D0070619C /* AccessibilitySpinButton.h in Headers */,
 				69A6CBAD1C6BE42C00B836E9 /* AccessibilitySVGElement.h in Headers */,
 				AAC08CF315F941FD00F1E188 /* AccessibilitySVGRoot.h in Headers */,
@@ -30793,6 +30818,7 @@
 				6E4ABCD5138EA0B70071D291 /* JSHTMLUnknownElement.h in Headers */,
 				E44614170CD6826900FADA75 /* JSHTMLVideoElement.h in Headers */,
 				81BE20D311F4BC3200915DFA /* JSIDBCursor.h in Headers */,
+				F050E17823AD70C50011CE47 /* PlatformTouchPoint.h in Headers */,
 				7C3D8EF01E0B21430023B084 /* JSIDBCursorDirection.h in Headers */,
 				C585A68311D4FB08004C3E4B /* JSIDBDatabase.h in Headers */,
 				C585A69711D4FB13004C3E4B /* JSIDBFactory.h in Headers */,
@@ -32698,9 +32724,11 @@
 				A7DBF8DE1276919C006B6008 /* TextCheckingHelper.h in Headers */,
 				B2C3DA3A0D006C1D00EF6F26 /* TextCodec.h in Headers */,
 				26E98A10130A9FCA008EB7B2 /* TextCodecASCIIFastPath.h in Headers */,
+				F050E16823AC9C080011CE47 /* PlatformTouchEvent.h in Headers */,
 				B2C3DA3C0D006C1D00EF6F26 /* TextCodecICU.h in Headers */,
 				B2C3DA3E0D006C1D00EF6F26 /* TextCodecLatin1.h in Headers */,
 				57EF5E601D20C83900171E60 /* TextCodecReplacement.h in Headers */,
+				F050E17223AD669F0011CE47 /* TouchEvent.h in Headers */,
 				B2C3DA400D006C1D00EF6F26 /* TextCodecUserDefined.h in Headers */,
 				B2C3DA420D006C1D00EF6F26 /* TextCodecUTF16.h in Headers */,
 				9343CB8212F25E510033C5EE /* TextCodecUTF8.h in Headers */,
@@ -33582,6 +33610,7 @@
 				CDDE02ED18B3ED6D00CF7FF1 /* CDMSessionAVFoundationObjC.mm in Sources */,
 				CDDE02F018B5651300CF7FF1 /* CDMSessionAVStreamSession.mm in Sources */,
 				CDE5959D1BF2757100A1CBE8 /* CDMSessionMediaSourceAVFObjC.mm in Sources */,
+				F050E17123AD669F0011CE47 /* TouchEvent.cpp in Sources */,
 				A14090FB1AA51E1D0091191A /* ContentFilterUnblockHandlerCocoa.mm in Sources */,
 				07AFF4231EFB144900B545B3 /* CoreAudioCaptureSourceIOS.mm in Sources */,
 				46C696CC1E7205FC00597937 /* CPUMonitor.cpp in Sources */,
@@ -33655,6 +33684,7 @@
 				51058ADF1D67C229009A538C /* MockGamepad.cpp in Sources */,
 				51058AE11D67C229009A538C /* MockGamepadProvider.cpp in Sources */,
 				CDF2B0121820540600F2B424 /* MockMediaPlayerMediaSource.cpp in Sources */,
+				F050E17423AD6A800011CE47 /* DocumentTouch.cpp in Sources */,
 				CDF2B0141820540600F2B424 /* MockMediaSourcePrivate.cpp in Sources */,
 				CDF2B0161820540700F2B424 /* MockSourceBufferPrivate.cpp in Sources */,
 				2D9BF7421DBFDC27007A7D99 /* NavigatorEME.cpp in Sources */,
@@ -33740,6 +33770,7 @@
 				538EC8881F993F9C004D22A8 /* UnifiedSource23.cpp in Sources */,
 				DE5F85801FA1ABF4006DB63A /* UnifiedSource24-mm.mm in Sources */,
 				538EC8891F993F9D004D22A8 /* UnifiedSource24.cpp in Sources */,
+				F050E16E23AD66630011CE47 /* TouchList.cpp in Sources */,
 				DE5F85811FA1ABF4006DB63A /* UnifiedSource25-mm.mm in Sources */,
 				538EC88A1F993F9D004D22A8 /* UnifiedSource25.cpp in Sources */,
 				DE5F85821FA1ABF4006DB63A /* UnifiedSource26-mm.mm in Sources */,
@@ -34272,6 +34303,7 @@
 				2D8B92F1203D13E1009C868F /* UnifiedSource516.cpp in Sources */,
 				2D8B92F2203D13E1009C868F /* UnifiedSource517.cpp in Sources */,
 				2D8B92F3203D13E1009C868F /* UnifiedSource518.cpp in Sources */,
+				F050E16A23AD660C0011CE47 /* Touch.cpp in Sources */,
 				2D8B92F4203D13E1009C868F /* UnifiedSource519.cpp in Sources */,
 				2D8B92F5203D13E1009C868F /* UnifiedSource520.cpp in Sources */,
 				2D8B92F6203D13E1009C868F /* UnifiedSource521.cpp in Sources */,
diff --git a/Source/WebCore/css/MediaQueryEvaluator.cpp b/Source/WebCore/css/MediaQueryEvaluator.cpp
index 2ac163067f2e00a595c425a91fc3a55617baf689..0f492b539ed56f7f963fdf5a72ab75f8f7ea89ab 100644
--- a/Source/WebCore/css/MediaQueryEvaluator.cpp
+++ b/Source/WebCore/css/MediaQueryEvaluator.cpp
@@ -387,7 +387,7 @@ static bool deviceAspectRatioEvaluate(CSSValue* value, const CSSToLengthConversi
     if (!value)
         return true;
 
-    auto size = screenRect(frame.mainFrame().view()).size();
+    auto size = frame.page()->screenSize();
     bool result = compareAspectRatioValue(value, size.width(), size.height(), op);
     LOG_WITH_STREAM(MediaQueries, stream << "  deviceAspectRatioEvaluate: " << op << " " << aspectRatioValueAsString(value) << " actual screen size " << size << ": " << result);
     return result;
@@ -505,7 +505,7 @@ static bool deviceHeightEvaluate(CSSValue* value, const CSSToLengthConversionDat
     if (!value)
         return true;
     int length;
-    auto height = screenRect(frame.mainFrame().view()).height();
+    auto height = frame.page()->screenSize().height();
     if (!computeLength(value, !frame.document()->inQuirksMode(), conversionData, length))
         return false;
 
@@ -520,8 +520,10 @@ static bool deviceWidthEvaluate(CSSValue* value, const CSSToLengthConversionData
     // assume if we have a device, assume non-zero
     if (!value)
         return true;
+    if (!frame.mainFrame().view())
+        return false;
     int length;
-    auto width = screenRect(frame.mainFrame().view()).width();
+    auto width = frame.page()->screenSize().width();
     if (!computeLength(value, !frame.document()->inQuirksMode(), conversionData, length))
         return false;
 
diff --git a/Source/WebCore/dom/UserGestureIndicator.cpp b/Source/WebCore/dom/UserGestureIndicator.cpp
index dfec93b644f72a51bad0bebf396da61c57f6e428..353833a7614a55566862c196bafc598a475536a1 100644
--- a/Source/WebCore/dom/UserGestureIndicator.cpp
+++ b/Source/WebCore/dom/UserGestureIndicator.cpp
@@ -56,8 +56,7 @@ UserGestureIndicator::UserGestureIndicator(Optional<ProcessingUserGestureState>
 
     if (state)
         currentToken() = UserGestureToken::create(state.value(), gestureType);
-
-    if (document && currentToken()->processingUserGesture() && state) {
+    if (document && state && currentToken()->processingUserGesture()) {
         document->updateLastHandledUserGestureTimestamp(currentToken()->startTime());
         if (processInteractionStyle == ProcessInteractionStyle::Immediate)
             ResourceLoadObserver::shared().logUserInteractionWithReducedTimeResolution(document->topDocument());
diff --git a/Source/WebCore/html/FileInputType.cpp b/Source/WebCore/html/FileInputType.cpp
index 4e41fd3f807e8f34bfef3f63f0ba6119a619821e..1f7be602cb2134f8867bf95afe0c9337bce57055 100644
--- a/Source/WebCore/html/FileInputType.cpp
+++ b/Source/WebCore/html/FileInputType.cpp
@@ -36,6 +36,7 @@
 #include "HTMLNames.h"
 #include "Icon.h"
 #include "InputTypeNames.h"
+#include "InspectorInstrumentation.h"
 #include "LocalizedStrings.h"
 #include "RenderFileUploadControl.h"
 #include "RuntimeEnabledFeatures.h"
@@ -205,6 +206,11 @@ void FileInputType::handleDOMActivateEvent(Event& event)
     if (input.isDisabledFormControl())
         return;
 
+    bool intercept = false;
+    InspectorInstrumentation::runOpenPanel(input.document().frame(), element(), &intercept);
+    if (intercept)
+        return;
+
     if (!UserGestureIndicator::processingUserGesture())
         return;
 
diff --git a/Source/WebCore/inspector/InspectorController.cpp b/Source/WebCore/inspector/InspectorController.cpp
index 7d50ddc7a38a3723e4ee7d66ca97c8acb37c726a..7ee70c6dd4bb84012a682ed648dc3c0cbd8ad211 100644
--- a/Source/WebCore/inspector/InspectorController.cpp
+++ b/Source/WebCore/inspector/InspectorController.cpp
@@ -510,4 +510,24 @@ void InspectorController::didComposite(Frame& frame)
     InspectorInstrumentation::didComposite(frame);
 }
 
+void InspectorController::pauseWhenShown()
+{
+    m_pauseWhenShown = true;
+}
+
+void InspectorController::resumeIfPausedInNewWindow()
+{
+    m_pauseWhenShown = false;
+}
+
+void InspectorController::didShowNewWindow()
+{
+    if (!m_pauseWhenShown)
+        return;
+    while (m_pauseWhenShown) {
+        if (RunLoop::cycle() == RunLoop::CycleResult::Stop)
+            break;
+    }
+}
+
 } // namespace WebCore
diff --git a/Source/WebCore/inspector/InspectorController.h b/Source/WebCore/inspector/InspectorController.h
index cd4497c9cdf7e3dc7fe89ffdbf188d47f2aaa00d..8cadb40ac6cd04fa3921866a6c4d3142518cb0c3 100644
--- a/Source/WebCore/inspector/InspectorController.h
+++ b/Source/WebCore/inspector/InspectorController.h
@@ -100,6 +100,10 @@ public:
     WEBCORE_EXPORT void willComposite(Frame&);
     WEBCORE_EXPORT void didComposite(Frame&);
 
+    WEBCORE_EXPORT void pauseWhenShown();
+    WEBCORE_EXPORT void resumeIfPausedInNewWindow();
+    WEBCORE_EXPORT void didShowNewWindow();
+
     bool isUnderTest() const { return m_isUnderTest; }
     void setIsUnderTest(bool isUnderTest) { m_isUnderTest = isUnderTest; }
     WEBCORE_EXPORT void evaluateForTestInFrontend(const String& script);
@@ -149,6 +153,7 @@ private:
     bool m_isAutomaticInspection { false };
     bool m_pauseAfterInitialization = { false };
     bool m_didCreateLazyAgents { false };
+    bool m_pauseWhenShown { false };
 };
 
 } // namespace WebCore
diff --git a/Source/WebCore/inspector/InspectorInstrumentation.cpp b/Source/WebCore/inspector/InspectorInstrumentation.cpp
index 3dc7b494d6656a91c7dd9c68e1c9eaf789666d01..54ff59eaec197fdd12248cd4542b91db2b5bb83a 100644
--- a/Source/WebCore/inspector/InspectorInstrumentation.cpp
+++ b/Source/WebCore/inspector/InspectorInstrumentation.cpp
@@ -621,6 +621,12 @@ void InspectorInstrumentation::didFailLoadingImpl(InstrumentingAgents& instrumen
         consoleAgent->didFailLoading(identifier, error); // This should come AFTER resource notification, front-end relies on this.
 }
 
+void InspectorInstrumentation::didReceiveMainResourceErrorImpl(InstrumentingAgents& instrumentingAgents, Frame& frame, const ResourceError&)
+{
+    if (auto* pageRuntimeAgent = instrumentingAgents.pageRuntimeAgent())
+        pageRuntimeAgent->didReceiveMainResourceError(frame);
+}
+
 void InspectorInstrumentation::willLoadXHRSynchronouslyImpl(InstrumentingAgents& instrumentingAgents)
 {
     if (InspectorNetworkAgent* networkAgent = instrumentingAgents.inspectorNetworkAgent())
@@ -653,20 +659,17 @@ void InspectorInstrumentation::didReceiveScriptResponseImpl(InstrumentingAgents&
 
 void InspectorInstrumentation::domContentLoadedEventFiredImpl(InstrumentingAgents& instrumentingAgents, Frame& frame)
 {
-    if (!frame.isMainFrame())
-        return;
-
     if (InspectorPageAgent* pageAgent = instrumentingAgents.inspectorPageAgent())
-        pageAgent->domContentEventFired();
+        pageAgent->domContentEventFired(frame);
 }
 
 void InspectorInstrumentation::loadEventFiredImpl(InstrumentingAgents& instrumentingAgents, Frame* frame)
 {
-    if (!frame || !frame->isMainFrame())
+    if (!frame)
         return;
 
     if (InspectorPageAgent* pageAgent = instrumentingAgents.inspectorPageAgent())
-        pageAgent->loadEventFired();
+        pageAgent->loadEventFired(*frame);
 }
 
 void InspectorInstrumentation::frameDetachedFromParentImpl(InstrumentingAgents& instrumentingAgents, Frame& frame)
@@ -744,12 +747,6 @@ void InspectorInstrumentation::frameDocumentUpdatedImpl(InstrumentingAgents& ins
         pageDOMDebuggerAgent->frameDocumentUpdated(frame);
 }
 
-void InspectorInstrumentation::loaderDetachedFromFrameImpl(InstrumentingAgents& instrumentingAgents, DocumentLoader& loader)
-{
-    if (InspectorPageAgent* inspectorPageAgent = instrumentingAgents.inspectorPageAgent())
-        inspectorPageAgent->loaderDetachedFromFrame(loader);
-}
-
 void InspectorInstrumentation::frameStartedLoadingImpl(InstrumentingAgents& instrumentingAgents, Frame& frame)
 {
     if (frame.isMainFrame()) {
@@ -786,6 +783,12 @@ void InspectorInstrumentation::frameClearedScheduledNavigationImpl(Instrumenting
         inspectorPageAgent->frameClearedScheduledNavigation(frame);
 }
 
+void InspectorInstrumentation::didNavigateWithinPageImpl(InstrumentingAgents& instrumentingAgents, Frame& frame)
+{
+    if (InspectorPageAgent* inspectorPageAgent = instrumentingAgents.inspectorPageAgent())
+        inspectorPageAgent->didNavigateWithinPage(frame);
+}
+
 void InspectorInstrumentation::defaultAppearanceDidChangeImpl(InstrumentingAgents& instrumentingAgents, bool useDarkAppearance)
 {
     if (InspectorPageAgent* inspectorPageAgent = instrumentingAgents.inspectorPageAgent())
@@ -1288,6 +1291,31 @@ void InspectorInstrumentation::renderLayerDestroyedImpl(InstrumentingAgents& ins
         layerTreeAgent->renderLayerDestroyed(renderLayer);
 }
 
+void InspectorInstrumentation::runOpenPanelImpl(InstrumentingAgents& instrumentingAgents, HTMLInputElement* element, bool* intercept)
+{
+    if (InspectorPageAgent* pageAgent = instrumentingAgents.inspectorPageAgent())
+        pageAgent->runOpenPanel(element, intercept);
+}
+
+void InspectorInstrumentation::frameAttachedImpl(InstrumentingAgents& instrumentingAgents, Frame& frame) {
+    if (InspectorPageAgent* pageAgent = instrumentingAgents.inspectorPageAgent())
+        pageAgent->frameAttached(frame);
+}
+
+bool InspectorInstrumentation::shouldBypassCSPImpl(InstrumentingAgents& instrumentingAgents)
+{
+    if (InspectorPageAgent* pageAgent = instrumentingAgents.inspectorPageAgent())
+        return pageAgent->shouldBypassCSP();
+    return false;
+}
+
+bool InspectorInstrumentation::interceptRequestImpl(InstrumentingAgents& instrumentingAgents, ResourceLoader& loader, Function<void(bool handled)>&& handler)
+{
+    if (InspectorNetworkAgent* networkAgent = instrumentingAgents.inspectorNetworkAgent())
+        return networkAgent->interceptRequest(loader, WTFMove(handler));
+    return false;
+}
+
 InstrumentingAgents& InspectorInstrumentation::instrumentingAgentsForWorkerGlobalScope(WorkerGlobalScope& workerGlobalScope)
 {
     return workerGlobalScope.inspectorController().m_instrumentingAgents;
diff --git a/Source/WebCore/inspector/InspectorInstrumentation.h b/Source/WebCore/inspector/InspectorInstrumentation.h
index b246eaa559a75265c890dfa47d01d311c186a403..57460008e1925fe15ea37d1eee194836afed8370 100644
--- a/Source/WebCore/inspector/InspectorInstrumentation.h
+++ b/Source/WebCore/inspector/InspectorInstrumentation.h
@@ -45,11 +45,13 @@
 #include "HitTestResult.h"
 #include "InspectorInstrumentationPublic.h"
 #include "Page.h"
+#include "ResourceLoader.h"
 #include "StorageArea.h"
 #include "WebAnimation.h"
 #include <JavaScriptCore/ConsoleMessage.h>
 #include <initializer_list>
 #include <wtf/CompletionHandler.h>
+#include <wtf/Function.h>
 #include <wtf/MemoryPressureHandler.h>
 #include <wtf/RefPtr.h>
 
@@ -77,6 +79,7 @@ class DOMWrapperWorld;
 class Document;
 class DocumentLoader;
 class EventListener;
+class HTMLInputElement;
 class HTTPHeaderMap;
 class InspectorTimelineAgent;
 class InstrumentingAgents;
@@ -197,6 +200,7 @@ public:
     static void didReceiveData(Frame*, unsigned long identifier, const char* data, int dataLength, int encodedDataLength);
     static void didFinishLoading(Frame*, DocumentLoader*, unsigned long identifier, const NetworkLoadMetrics&, ResourceLoader*);
     static void didFailLoading(Frame*, DocumentLoader*, unsigned long identifier, const ResourceError&);
+    static void didReceiveMainResourceError(Frame&, const ResourceError&);
 
     static void willSendRequest(WorkerGlobalScope&, unsigned long identifier, ResourceRequest&);
     static void didReceiveResourceResponse(WorkerGlobalScope&, unsigned long identifier, const ResourceResponse&);
@@ -223,11 +227,11 @@ public:
     static void frameDetachedFromParent(Frame&);
     static void didCommitLoad(Frame&, DocumentLoader*);
     static void frameDocumentUpdated(Frame&);
-    static void loaderDetachedFromFrame(Frame&, DocumentLoader&);
     static void frameStartedLoading(Frame&);
     static void frameStoppedLoading(Frame&);
     static void frameScheduledNavigation(Frame&, Seconds delay);
     static void frameClearedScheduledNavigation(Frame&);
+    static void didNavigateWithinPage(Frame&);
     static void defaultAppearanceDidChange(Page&, bool useDarkAppearance);
     static void willDestroyCachedResource(CachedResource&);
 
@@ -317,6 +321,11 @@ public:
     static void layerTreeDidChange(Page*);
     static void renderLayerDestroyed(Page*, const RenderLayer&);
 
+    static void runOpenPanel(Frame*, HTMLInputElement*, bool*);
+    static void frameAttached(Frame*);
+    static bool shouldBypassCSP(ScriptExecutionContext*);
+    static bool interceptRequest(ResourceLoader&, Function<void(bool handled)>&&);
+
     static void frontendCreated();
     static void frontendDeleted();
     static bool hasFrontends() { return InspectorInstrumentationPublic::hasFrontends(); }
@@ -417,6 +426,7 @@ private:
     static void didReceiveDataImpl(InstrumentingAgents&, unsigned long identifier, const char* data, int dataLength, int encodedDataLength);
     static void didFinishLoadingImpl(InstrumentingAgents&, unsigned long identifier, DocumentLoader*, const NetworkLoadMetrics&, ResourceLoader*);
     static void didFailLoadingImpl(InstrumentingAgents&, unsigned long identifier, DocumentLoader*, const ResourceError&);
+    static void didReceiveMainResourceErrorImpl(InstrumentingAgents&, Frame&, const ResourceError&);
     static void willLoadXHRSynchronouslyImpl(InstrumentingAgents&);
     static void didLoadXHRSynchronouslyImpl(InstrumentingAgents&);
     static void scriptImportedImpl(InstrumentingAgents&, unsigned long identifier, const String& sourceString);
@@ -427,11 +437,11 @@ private:
     static void frameDetachedFromParentImpl(InstrumentingAgents&, Frame&);
     static void didCommitLoadImpl(InstrumentingAgents&, Frame&, DocumentLoader*);
     static void frameDocumentUpdatedImpl(InstrumentingAgents&, Frame&);
-    static void loaderDetachedFromFrameImpl(InstrumentingAgents&, DocumentLoader&);
     static void frameStartedLoadingImpl(InstrumentingAgents&, Frame&);
     static void frameStoppedLoadingImpl(InstrumentingAgents&, Frame&);
     static void frameScheduledNavigationImpl(InstrumentingAgents&, Frame&, Seconds delay);
     static void frameClearedScheduledNavigationImpl(InstrumentingAgents&, Frame&);
+    static void didNavigateWithinPageImpl(InstrumentingAgents&, Frame&);
     static void defaultAppearanceDidChangeImpl(InstrumentingAgents&, bool useDarkAppearance);
     static void willDestroyCachedResourceImpl(CachedResource&);
 
@@ -517,6 +527,11 @@ private:
     static void layerTreeDidChangeImpl(InstrumentingAgents&);
     static void renderLayerDestroyedImpl(InstrumentingAgents&, const RenderLayer&);
 
+    static void runOpenPanelImpl(InstrumentingAgents&, HTMLInputElement*, bool*);
+    static void frameAttachedImpl(InstrumentingAgents&, Frame&);
+    static bool shouldBypassCSPImpl(InstrumentingAgents&);
+    static bool interceptRequestImpl(InstrumentingAgents&, ResourceLoader&, Function<void(bool handled)>&&);
+
     static InstrumentingAgents& instrumentingAgentsForPage(Page&);
     static InstrumentingAgents& instrumentingAgentsForWorkerGlobalScope(WorkerGlobalScope&);
 
@@ -1097,6 +1112,13 @@ inline void InspectorInstrumentation::didFailLoading(Frame* frame, DocumentLoade
         didFailLoadingImpl(*instrumentingAgents, identifier, loader, error);
 }
 
+inline void InspectorInstrumentation::didReceiveMainResourceError(Frame& frame, const ResourceError& error)
+{
+    FAST_RETURN_IF_NO_FRONTENDS(void());
+    if (InstrumentingAgents* instrumentingAgents = instrumentingAgentsForFrame(frame))
+        didReceiveMainResourceErrorImpl(*instrumentingAgents, frame, error);
+}
+
 inline void InspectorInstrumentation::didFailLoading(WorkerGlobalScope& workerGlobalScope, unsigned long identifier, const ResourceError& error)
 {
     didFailLoadingImpl(instrumentingAgentsForWorkerGlobalScope(workerGlobalScope), identifier, nullptr, error);
@@ -1192,13 +1214,6 @@ inline void InspectorInstrumentation::frameDocumentUpdated(Frame& frame)
         frameDocumentUpdatedImpl(*instrumentingAgents, frame);
 }
 
-inline void InspectorInstrumentation::loaderDetachedFromFrame(Frame& frame, DocumentLoader& loader)
-{
-    FAST_RETURN_IF_NO_FRONTENDS(void());
-    if (InstrumentingAgents* instrumentingAgents = instrumentingAgentsForFrame(frame))
-        loaderDetachedFromFrameImpl(*instrumentingAgents, loader);
-}
-
 inline void InspectorInstrumentation::frameStartedLoading(Frame& frame)
 {
     FAST_RETURN_IF_NO_FRONTENDS(void());
@@ -1227,6 +1242,13 @@ inline void InspectorInstrumentation::frameClearedScheduledNavigation(Frame& fra
         frameClearedScheduledNavigationImpl(*instrumentingAgents, frame);
 }
 
+inline void InspectorInstrumentation::didNavigateWithinPage(Frame& frame)
+{
+    FAST_RETURN_IF_NO_FRONTENDS(void());
+    if (InstrumentingAgents* instrumentingAgents = instrumentingAgentsForFrame(frame))
+        didNavigateWithinPageImpl(*instrumentingAgents, frame);
+}
+
 inline void InspectorInstrumentation::defaultAppearanceDidChange(Page& page, bool useDarkAppearance)
 {
     FAST_RETURN_IF_NO_FRONTENDS(void());
@@ -1677,6 +1699,36 @@ inline void InspectorInstrumentation::renderLayerDestroyed(Page* page, const Ren
         renderLayerDestroyedImpl(*instrumentingAgents, renderLayer);
 }
 
+inline void InspectorInstrumentation::runOpenPanel(Frame* frame, HTMLInputElement* element, bool* intercept)
+{
+    FAST_RETURN_IF_NO_FRONTENDS(void());
+    if (InstrumentingAgents* instrumentingAgents = instrumentingAgentsForFrame(*frame))
+        runOpenPanelImpl(*instrumentingAgents, element, intercept);
+}
+
+inline void InspectorInstrumentation::frameAttached(Frame* frame)
+{
+    FAST_RETURN_IF_NO_FRONTENDS(void());
+    if (InstrumentingAgents* instrumentingAgents = instrumentingAgentsForFrame(frame))
+        frameAttachedImpl(*instrumentingAgents, *frame);
+}
+
+inline bool InspectorInstrumentation::shouldBypassCSP(ScriptExecutionContext* context)
+{
+    FAST_RETURN_IF_NO_FRONTENDS(false);
+    if (InstrumentingAgents* instrumentingAgents = instrumentingAgentsForContext(context))
+        return shouldBypassCSPImpl(*instrumentingAgents);
+    return false;
+}
+
+inline bool InspectorInstrumentation::interceptRequest(ResourceLoader& loader, Function<void(bool handled)>&& handler)
+{
+    FAST_RETURN_IF_NO_FRONTENDS(false);
+    if (InstrumentingAgents* instrumentingAgents = instrumentingAgentsForFrame(loader.frame()))
+        return interceptRequestImpl(*instrumentingAgents, loader, WTFMove(handler));
+    return false;
+}
+
 inline InstrumentingAgents* InspectorInstrumentation::instrumentingAgentsForContext(ScriptExecutionContext* context)
 {
     return context ? instrumentingAgentsForContext(*context) : nullptr;
diff --git a/Source/WebCore/inspector/InspectorInstrumentationWebKit.cpp b/Source/WebCore/inspector/InspectorInstrumentationWebKit.cpp
index 954aaf121a9fa507d83bc10ae37de1f128f7dcfc..9f16be3dbcf4857742ec2ab131e2b2f962a2a47c 100644
--- a/Source/WebCore/inspector/InspectorInstrumentationWebKit.cpp
+++ b/Source/WebCore/inspector/InspectorInstrumentationWebKit.cpp
@@ -30,6 +30,11 @@
 
 namespace WebCore {
 
+bool InspectorInstrumentationWebKit::interceptRequestInternal(ResourceLoader& loader, Function<void(bool handled)>&& handler)
+{
+    return InspectorInstrumentation::interceptRequest(loader, WTFMove(handler));
+}
+
 bool InspectorInstrumentationWebKit::shouldInterceptResponseInternal(const Frame& frame, const ResourceResponse& response)
 {
     return InspectorInstrumentation::shouldInterceptResponse(frame, response);
diff --git a/Source/WebCore/inspector/InspectorInstrumentationWebKit.h b/Source/WebCore/inspector/InspectorInstrumentationWebKit.h
index b67e89b80b4e7a8586cac81ade5d58a1bcb0d431..c468bc0981d1fb13272b28095f9f7584840b5861 100644
--- a/Source/WebCore/inspector/InspectorInstrumentationWebKit.h
+++ b/Source/WebCore/inspector/InspectorInstrumentationWebKit.h
@@ -27,6 +27,7 @@
 
 #include "InspectorInstrumentationPublic.h"
 #include <wtf/CompletionHandler.h>
+#include <wtf/Function.h>
 
 namespace WebCore {
 
@@ -36,14 +37,22 @@ class SharedBuffer;
 
 class WEBCORE_EXPORT InspectorInstrumentationWebKit {
 public:
+    static bool interceptRequest(ResourceLoader&, Function<void(bool handled)>&&);
     static bool shouldInterceptResponse(const Frame*, const ResourceResponse&);
     static void interceptResponse(const Frame*, const ResourceResponse&, unsigned long identifier, CompletionHandler<void(const ResourceResponse&, RefPtr<SharedBuffer>)>&&);
 
 private:
+    static bool interceptRequestInternal(ResourceLoader&, Function<void(bool handled)>&&);
     static bool shouldInterceptResponseInternal(const Frame&, const ResourceResponse&);
     static void interceptResponseInternal(const Frame&, const ResourceResponse&, unsigned long identifier, CompletionHandler<void(const ResourceResponse&, RefPtr<SharedBuffer>)>&&);
 };
 
+inline bool InspectorInstrumentationWebKit::interceptRequest(ResourceLoader& loader, Function<void(bool handled)>&& handler)
+{
+    FAST_RETURN_IF_NO_FRONTENDS(false);
+    return interceptRequestInternal(loader, WTFMove(handler));
+}
+
 inline bool InspectorInstrumentationWebKit::shouldInterceptResponse(const Frame* frame, const ResourceResponse& response)
 {
     FAST_RETURN_IF_NO_FRONTENDS(false);
diff --git a/Source/WebCore/inspector/agents/InspectorDOMAgent.cpp b/Source/WebCore/inspector/agents/InspectorDOMAgent.cpp
index d2ca5bbe109aaad182bae185c4d52d8aaecda84d..4fa24557c5a86a967e8d13579e75ce50d72947a4 100644
--- a/Source/WebCore/inspector/agents/InspectorDOMAgent.cpp
+++ b/Source/WebCore/inspector/agents/InspectorDOMAgent.cpp
@@ -61,12 +61,16 @@
 #include "Event.h"
 #include "EventListener.h"
 #include "EventNames.h"
+#include "File.h"
+#include "FileList.h"
 #include "Frame.h"
 #include "FrameTree.h"
 #include "FrameView.h"
 #include "FullscreenManager.h"
+#include "FloatQuad.h"
 #include "HTMLElement.h"
 #include "HTMLFrameOwnerElement.h"
+#include "HTMLInputElement.h"
 #include "HTMLMediaElement.h"
 #include "HTMLNames.h"
 #include "HTMLParserIdioms.h"
@@ -93,11 +97,14 @@
 #include "Page.h"
 #include "Pasteboard.h"
 #include "PseudoElement.h"
+#include "RenderLayer.h"
+#include "RenderObject.h"
 #include "RenderStyle.h"
 #include "RenderStyleConstants.h"
 #include "ScriptState.h"
 #include "SelectorChecker.h"
 #include "ShadowRoot.h"
+#include "SharedBuffer.h"
 #include "StaticNodeList.h"
 #include "StyleProperties.h"
 #include "StyleResolver.h"
@@ -128,7 +135,8 @@ using namespace HTMLNames;
 static const size_t maxTextSize = 10000;
 static const UChar ellipsisUChar[] = { 0x2026, 0 };
 
-static Color parseColor(const JSON::Object* colorObject)
+// static
+Color InspectorDOMAgent::parseColor(const JSON::Object* colorObject)
 {
     if (!colorObject)
         return Color::transparent;
@@ -157,7 +165,7 @@ static Color parseConfigColor(const String& fieldName, const JSON::Object* confi
     RefPtr<JSON::Object> colorObject;
     configObject->getObject(fieldName, colorObject);
 
-    return parseColor(colorObject.get());
+    return InspectorDOMAgent::parseColor(colorObject.get());
 }
 
 static bool parseQuad(const JSON::Array& quadArray, FloatQuad* quad)
@@ -438,6 +446,20 @@ Node* InspectorDOMAgent::assertNode(ErrorString& errorString, int nodeId)
     return node;
 }
 
+Node* InspectorDOMAgent::assertNode(ErrorString& errorString, const int* nodeId, const String* objectId)
+{
+    Node* node = nullptr;
+    if (nodeId) {
+        node = assertNode(errorString, *nodeId);
+    } else if (objectId) {
+        node = nodeForObjectId(*objectId);
+        if (!node)
+            errorString = "Missing node for given objectId"_s;
+    } else
+        errorString = "Either nodeId or objectId must be specified"_s;
+    return node;
+}
+
 Document* InspectorDOMAgent::assertDocument(ErrorString& errorString, int nodeId)
 {
     Node* node = assertNode(errorString, nodeId);
@@ -1329,16 +1351,7 @@ void InspectorDOMAgent::highlightSelector(ErrorString& errorString, const JSON::
 
 void InspectorDOMAgent::highlightNode(ErrorString& errorString, const JSON::Object& highlightInspectorObject, const int* nodeId, const String* objectId)
 {
-    Node* node = nullptr;
-    if (nodeId)
-        node = assertNode(errorString, *nodeId);
-    else if (objectId) {
-        node = nodeForObjectId(*objectId);
-        if (!node)
-            errorString = "Missing node for given objectId"_s;
-    } else
-        errorString = "Either nodeId or objectId must be specified"_s;
-
+    Node* node = assertNode(errorString, nodeId, objectId);
     if (!node)
         return;
 
@@ -1486,18 +1499,147 @@ void InspectorDOMAgent::setInspectedNode(ErrorString& errorString, int nodeId)
     m_suppressEventListenerChangedEvent = false;
 }
 
-void InspectorDOMAgent::resolveNode(ErrorString& errorString, int nodeId, const String* objectGroup, RefPtr<Inspector::Protocol::Runtime::RemoteObject>& result)
+static FloatPoint contentsToRootView(FrameView& containingView, const FloatPoint& point)
 {
-    String objectGroupName = objectGroup ? *objectGroup : emptyString();
-    Node* node = assertNode(errorString, nodeId);
+    return containingView.convertToRootView(point - toFloatSize(containingView.documentScrollPositionRelativeToViewOrigin()));
+}
+
+static void frameQuadToViewport(FrameView& containingView, FloatQuad& quad, float pageScaleFactor)
+{
+    // Return css (not dip) coordinates by scaling back.
+    quad.setP1(contentsToRootView(containingView, quad.p1()).scaled(1 / pageScaleFactor));
+    quad.setP2(contentsToRootView(containingView, quad.p2()).scaled(1 / pageScaleFactor));
+    quad.setP3(contentsToRootView(containingView, quad.p3()).scaled(1 / pageScaleFactor));
+    quad.setP4(contentsToRootView(containingView, quad.p4()).scaled(1 / pageScaleFactor));
+}
+
+static RefPtr<Inspector::Protocol::DOM::Quad> buildObjectForQuad(const FloatQuad& quad)
+{
+    auto result = Inspector::Protocol::DOM::Quad::create();
+    result->addItem(quad.p1().x());
+    result->addItem(quad.p1().y());
+    result->addItem(quad.p2().x());
+    result->addItem(quad.p2().y());
+    result->addItem(quad.p3().x());
+    result->addItem(quad.p3().y());
+    result->addItem(quad.p4().x());
+    result->addItem(quad.p4().y());
+    return result;
+}
+
+static RefPtr<JSON::ArrayOf<Inspector::Protocol::DOM::Quad>> buildArrayOfQuads(const Vector<FloatQuad>& quads)
+{
+    auto result = JSON::ArrayOf<Inspector::Protocol::DOM::Quad>::create();
+    for (const auto& quad : quads)
+        result->addItem(buildObjectForQuad(quad));
+    return result;
+}
+
+void InspectorDOMAgent::describeNode(ErrorString& errorString, const String& objectId, Optional<String>& contentFrameId, Optional<String>& ownerFrameId)
+{
+    Node* node = nodeForObjectId(objectId);
+    if (!node) {
+        errorString = "Node not found"_s;
+        return;
+    }
+
+    auto* pageAgent = m_instrumentingAgents.inspectorPageAgent();
+    if (!pageAgent) {
+        errorString = "Page agent must be enabled"_s;
+        return;
+    }
+
+    String frameId = pageAgent->frameId(node->document().frame());
+    if (!frameId.isEmpty())
+        ownerFrameId = frameId;
+
+    if (is<HTMLFrameOwnerElement>(*node)) {
+        const auto& frameOwner = downcast<HTMLFrameOwnerElement>(*node);
+        String frameId = pageAgent->frameId(frameOwner.contentFrame());
+        if (!frameId.isEmpty())
+            contentFrameId = frameId;
+    }
+}
+
+void InspectorDOMAgent::scrollIntoViewIfNeeded(ErrorString& errorString, const String& objectId, const JSON::Object* rect)
+{
+    Node* node = nodeForObjectId(objectId);
+    if (!node) {
+        errorString = "Node not found"_s;
+        return;
+    }
+    node->document().updateLayoutIgnorePendingStylesheets();
+    if (!node->isConnected()) {
+        errorString = "Node is detached from document"_s;
+        return;
+    }
+    RenderObject* renderer = node->renderer();
+    if (!renderer) {
+        errorString = "Node does not have a layout object"_s;
+        return;
+    }
+    bool insideFixed;
+    LayoutRect absoluteBounds = renderer->absoluteBoundingBoxRect(true, &insideFixed);
+    if (rect) {
+        double x = 0.0;
+        double y = 0.0;
+        double width = 0.0;
+        double height = 0.0;
+        if (!rect->getDouble("x", x) || !rect->getDouble("y", y) || !rect->getDouble("width", width) || !rect->getDouble("height", height)) {
+            errorString = "Malformed rect"_s;
+            return;
+        }
+        absoluteBounds.setX(absoluteBounds.x() + LayoutUnit(x));
+        absoluteBounds.setY(absoluteBounds.y() + LayoutUnit(y));
+        absoluteBounds.setWidth(LayoutUnit(std::max(width, 1.0)));
+        absoluteBounds.setHeight(LayoutUnit(std::max(height, 1.0)));
+    }
+    // Note: we should use ScrollAlignment::alignCenterIfNotVisible, but
+    // RenderLayer insists on no horizontal scroll if enough of the rect is visible.
+    ScrollAlignment alignment = ScrollAlignment::alignCenterAlways;
+    renderer->scrollRectToVisible(absoluteBounds, insideFixed, { SelectionRevealMode::Reveal, alignment, alignment, ShouldAllowCrossOriginScrolling::Yes });
+}
+
+void InspectorDOMAgent::getContentQuads(ErrorString& errorString, const String& objectId, RefPtr<JSON::ArrayOf<Inspector::Protocol::DOM::Quad>>& contentQuads)
+{
+    Node* node = nodeForObjectId(objectId);
+    if (!node) {
+        errorString = "Node not found"_s;
+        return;
+    }
+    RenderObject* renderer = node->renderer();
+    if (!renderer) {
+        errorString = "Node doesn't have renderer"_s;
+        return;
+    }
+
+    // Ensure quads are up to date.
+    renderer->document().updateLayoutIgnorePendingStylesheets();
+
+    Frame* containingFrame = renderer->document().frame();
+    FrameView* containingView = containingFrame ? containingFrame->view() : nullptr;
+    if (!containingView) {
+        errorString = "Internal error: no containing view"_s;
+        return;
+    }
+    Vector<FloatQuad> quads;
+    renderer->absoluteQuads(quads);
+    for (auto& quad : quads)
+        frameQuadToViewport(*containingView, quad, m_inspectedPage.pageScaleFactor());
+    contentQuads = buildArrayOfQuads(quads);
+}
+
+void InspectorDOMAgent::resolveNode(ErrorString& errorString, const int* nodeId, const String* objectId, const int* contextId, const String* objectGroup, RefPtr<Inspector::Protocol::Runtime::RemoteObject>& result)
+{
+    Node* node = assertNode(errorString, nodeId, objectId);
     if (!node)
         return;
-    RefPtr<Inspector::Protocol::Runtime::RemoteObject> object = resolveNode(node, objectGroupName);
-    if (!object) {
+    String objectGroupName = objectGroup ? *objectGroup : emptyString();
+    result = resolveNode(node, objectGroupName, contextId);
+    if (!result) {
         errorString = "Missing injected script for given nodeId"_s;
         return;
     }
-    result = object;
 }
 
 void InspectorDOMAgent::getAttributes(ErrorString& errorString, int nodeId, RefPtr<JSON::ArrayOf<String>>& result)
@@ -2662,7 +2804,7 @@ void InspectorDOMAgent::pushNodeByPathToFrontend(ErrorString& errorString, const
         errorString = "Missing node for given path"_s;
 }
 
-RefPtr<Inspector::Protocol::Runtime::RemoteObject> InspectorDOMAgent::resolveNode(Node* node, const String& objectGroup)
+RefPtr<Inspector::Protocol::Runtime::RemoteObject> InspectorDOMAgent::resolveNode(Node* node, const String& objectGroup, const int* contextId)
 {
     Document* document = &node->document();
     if (auto* templateHost = document->templateDocumentHost())
@@ -2671,12 +2813,16 @@ RefPtr<Inspector::Protocol::Runtime::RemoteObject> InspectorDOMAgent::resolveNod
     if (!frame)
         return nullptr;
 
-    auto& state = *mainWorldExecState(frame);
-    auto injectedScript = m_injectedScriptManager.injectedScriptFor(&state);
+    InjectedScript injectedScript;
+    if (contextId) {
+        injectedScript = m_injectedScriptManager.injectedScriptForId(*contextId);
+    } else {
+        injectedScript = m_injectedScriptManager.injectedScriptFor(mainWorldExecState(frame));
+    }
     if (injectedScript.hasNoValue())
         return nullptr;
 
-    return injectedScript.wrapObject(nodeAsScriptValue(state, node), objectGroup);
+    return injectedScript.wrapObject(nodeAsScriptValue(*injectedScript.globalObject(), node), objectGroup);
 }
 
 Node* InspectorDOMAgent::scriptValueAsNode(JSC::JSValue value)
@@ -2697,4 +2843,46 @@ void InspectorDOMAgent::setAllowEditingUserAgentShadowTrees(ErrorString&, bool a
     m_allowEditingUserAgentShadowTrees = allow;
 }
 
+void InspectorDOMAgent::setInputFiles(ErrorString& errorString, const String& objectId, const JSON::Array& files) {
+    InjectedScript injectedScript = m_injectedScriptManager.injectedScriptForObjectId(objectId);
+    if (injectedScript.hasNoValue()) {
+        errorString = "Can not find element's context for given id"_s;
+        return;
+    }
+    Node* node = scriptValueAsNode(injectedScript.findObjectById(objectId));
+    if (!node) {
+        errorString = "Can not find element for given id"_s;
+        return;
+    }
+    if (node->nodeType() != Node::ELEMENT_NODE || node->nodeName() != "INPUT") {
+        errorString = "Not an input node"_s;
+        return;
+    }
+    HTMLInputElement* element = static_cast<HTMLInputElement*>(node);
+    Vector<Ref<File>> fileObjects;
+    for (unsigned i = 0; i < files.length(); ++i) {
+        RefPtr<JSON::Value> item = files.get(i);
+        RefPtr<JSON::Object> obj;
+        if (!item->asObject(obj)) {
+            errorString = "Invalid file payload format"_s;
+            return;
+        }
+        String name;
+        String type;
+        String data;
+        if (!obj->getString("name", name) || !obj->getString("type", type) || !obj->getString("data", data)) {
+            errorString = "Invalid file payload format"_s;
+            return;
+        }
+        Vector<uint8_t> buffer;
+        if (!base64Decode(data, buffer)) {
+            errorString = "Unable to decode given content"_s;
+            return;
+        }
+        fileObjects.append(File::create(Blob::create(SharedBuffer::create(WTFMove(buffer)), type), name));
+    }
+    RefPtr<FileList> fileList = FileList::create(WTFMove(fileObjects));
+    element->setFiles(WTFMove(fileList));
+}
+
 } // namespace WebCore
diff --git a/Source/WebCore/inspector/agents/InspectorDOMAgent.h b/Source/WebCore/inspector/agents/InspectorDOMAgent.h
index 7df0e83eb53d75c41c554f1401235ba21719414c..ae6f961a7b7fe63ece60e34210bf333bedef2eee 100644
--- a/Source/WebCore/inspector/agents/InspectorDOMAgent.h
+++ b/Source/WebCore/inspector/agents/InspectorDOMAgent.h
@@ -54,6 +54,7 @@ namespace WebCore {
 
 class AXCoreObject;
 class CharacterData;
+class Color;
 class DOMEditor;
 class Document;
 class Element;
@@ -88,6 +89,7 @@ public:
     static String toErrorString(Exception&&);
 
     static String documentURLString(Document*);
+    static Color parseColor(const JSON::Object*);
 
     // We represent embedded doms as a part of the same hierarchy. Hence we treat children of frame owners differently.
     // We also skip whitespace text nodes conditionally. Following methods encapsulate these specifics.
@@ -129,7 +131,7 @@ public:
     void performSearch(ErrorString&, const String& query, const JSON::Array* nodeIds, const bool* caseSensitive, String* searchId, int* resultCount) override;
     void getSearchResults(ErrorString&, const String& searchId, int fromIndex, int toIndex, RefPtr<JSON::ArrayOf<int>>&) override;
     void discardSearchResults(ErrorString&, const String& searchId) override;
-    void resolveNode(ErrorString&, int nodeId, const String* objectGroup, RefPtr<Inspector::Protocol::Runtime::RemoteObject>& result) override;
+    void resolveNode(ErrorString&, const int* nodeId, const String* objectId, const int* contextId, const String* objectGroup, RefPtr<Inspector::Protocol::Runtime::RemoteObject>& result) override;
     void getAttributes(ErrorString&, int nodeId, RefPtr<JSON::ArrayOf<String>>& result) override;
     void setInspectModeEnabled(ErrorString&, bool enabled, const JSON::Object* highlightConfig, const bool* showRulers) override;
     void requestNode(ErrorString&, const String& objectId, int* nodeId) override;
@@ -148,6 +150,10 @@ public:
     void focus(ErrorString&, int nodeId) override;
     void setInspectedNode(ErrorString&, int nodeId) override;
     void setAllowEditingUserAgentShadowTrees(ErrorString&, bool allow) final;
+    void describeNode(ErrorString&, const String& objectId, Optional<String>& contentFrameId, Optional<String>& ownerFrameId) override;
+    void scrollIntoViewIfNeeded(ErrorString&, const String& objectId, const JSON::Object* rect) override;
+    void getContentQuads(ErrorString&, const String& objectId, RefPtr<JSON::ArrayOf<Inspector::Protocol::DOM::Quad>>&) override;
+    void setInputFiles(ErrorString&, const String& objectId, const JSON::Array& files) override;
 
     // InspectorInstrumentation
     int identifierForNode(Node&);
@@ -185,7 +191,7 @@ public:
     Node* nodeForId(int nodeId);
     int boundNodeId(const Node*);
 
-    RefPtr<Inspector::Protocol::Runtime::RemoteObject> resolveNode(Node*, const String& objectGroup);
+    RefPtr<Inspector::Protocol::Runtime::RemoteObject> resolveNode(Node*, const String& objectGroup, const int* contextId);
     bool handleMousePress();
     void mouseDidMoveOverElement(const HitTestResult&, unsigned modifierFlags);
     void inspect(Node*);
@@ -196,12 +202,15 @@ public:
     void reset();
 
     Node* assertNode(ErrorString&, int nodeId);
+    Node* assertNode(ErrorString&, const int* nodeId, const String* objectId);
     Element* assertElement(ErrorString&, int nodeId);
     Document* assertDocument(ErrorString&, int nodeId);
 
     bool hasBreakpointForEventListener(EventTarget&, const AtomString& eventType, EventListener&, bool capture);
     int idForEventListener(EventTarget&, const AtomString& eventType, EventListener&, bool capture);
 
+    Node* nodeForObjectId(const String& objectId);
+
 private:
 #if ENABLE(VIDEO)
     void mediaMetricsTimerFired();
@@ -228,9 +237,8 @@ private:
     Ref<Inspector::Protocol::DOM::EventListener> buildObjectForEventListener(const RegisteredEventListener&, int identifier, EventTarget&, const AtomString& eventType, bool disabled, bool hasBreakpoint);
     RefPtr<Inspector::Protocol::DOM::AccessibilityProperties> buildObjectForAccessibilityProperties(Node*);
     void processAccessibilityChildren(AXCoreObject&, JSON::ArrayOf<int>&);
-    
+
     Node* nodeForPath(const String& path);
-    Node* nodeForObjectId(const String& objectId);
 
     void discardBindings();
 
diff --git a/Source/WebCore/inspector/agents/InspectorDOMStorageAgent.h b/Source/WebCore/inspector/agents/InspectorDOMStorageAgent.h
index b578660fbb3ce176e4e0aeb5a22021dc880e47f0..a7c968bc9f88c7d26e1887bb53106b4af2464753 100644
--- a/Source/WebCore/inspector/agents/InspectorDOMStorageAgent.h
+++ b/Source/WebCore/inspector/agents/InspectorDOMStorageAgent.h
@@ -40,6 +40,7 @@ class DOMStorageFrontendDispatcher;
 
 namespace WebCore {
 
+class Color;
 class Frame;
 class Page;
 class SecurityOrigin;
diff --git a/Source/WebCore/inspector/agents/InspectorNetworkAgent.cpp b/Source/WebCore/inspector/agents/InspectorNetworkAgent.cpp
index ee9edb30dd7b3461c4d491dfaf7929011d498bc9..71b51b0261494112b23800fe02f5e31bb90769bb 100644
--- a/Source/WebCore/inspector/agents/InspectorNetworkAgent.cpp
+++ b/Source/WebCore/inspector/agents/InspectorNetworkAgent.cpp
@@ -44,6 +44,7 @@
 #include "DocumentLoader.h"
 #include "DocumentThreadableLoader.h"
 #include "Frame.h"
+#include "FormData.h"
 #include "FrameLoader.h"
 #include "HTTPHeaderMap.h"
 #include "HTTPHeaderNames.h"
@@ -56,6 +57,7 @@
 #include "MIMETypeRegistry.h"
 #include "MemoryCache.h"
 #include "NetworkResourcesData.h"
+#include "NetworkStateNotifier.h"
 #include "Page.h"
 #include "PlatformStrategies.h"
 #include "ProgressTracker.h"
@@ -99,6 +101,11 @@ using namespace Inspector;
 
 namespace {
 
+String inspectorInitiatorPrefix()
+{
+    return "InspectorPageAgent.navigate referrer:"_s;
+}
+
 class InspectorThreadableLoaderClient final : public ThreadableLoaderClient {
     WTF_MAKE_NONCOPYABLE(InspectorThreadableLoaderClient);
 public:
@@ -453,6 +460,13 @@ void InspectorNetworkAgent::willSendRequest(unsigned long identifier, DocumentLo
     for (auto& entry : m_extraRequestHeaders)
         request.setHTTPHeaderField(entry.key, entry.value);
 
+    if (request.initiatorIdentifier().startsWith(inspectorInitiatorPrefix())) {
+        String referrer = request.initiatorIdentifier().substring(inspectorInitiatorPrefix().length());
+        if (!referrer.isEmpty())
+            request.setHTTPReferrer(referrer);
+        request.setInitiatorIdentifier(String());
+    }
+
     auto protocolResourceType = InspectorPageAgent::resourceTypeJSON(type);
 
     Document* document = loader && loader->frame() ? loader->frame()->document() : nullptr;
@@ -841,6 +855,7 @@ void InspectorNetworkAgent::disable(ErrorString&)
     m_resourcesData->clear();
     m_extraRequestHeaders.clear();
 
+    continuePendingRequests();
     continuePendingResponses();
 
     setResourceCachingDisabled(false);
@@ -864,6 +879,16 @@ bool InspectorNetworkAgent::shouldIntercept(URL url)
     return false;
 }
 
+void InspectorNetworkAgent::continuePendingRequests()
+{
+    for (auto& pendingRequest : m_pendingInterceptRequests.values()) {
+        ResourceLoader* loader = pendingRequest->m_loader.get();
+        if (loader->identifier())
+            pendingRequest->m_callback(false);
+    }
+    m_pendingInterceptRequests.clear();
+}
+
 void InspectorNetworkAgent::continuePendingResponses()
 {
     for (auto& pendingInterceptResponse : m_pendingInterceptResponses.values())
@@ -1020,17 +1045,15 @@ void InspectorNetworkAgent::resolveWebSocket(ErrorString& errorString, const Str
     result = injectedScript.wrapObject(webSocketAsScriptValue(state, webSocket), objectGroupName);
 }
 
-void InspectorNetworkAgent::setInterceptionEnabled(ErrorString& errorString, bool enabled)
+void InspectorNetworkAgent::setInterceptionEnabled(ErrorString&, bool enabled, const bool* interceptRequests)
 {
-    if (m_interceptionEnabled == enabled) {
-        errorString = m_interceptionEnabled ? "Interception already enabled"_s : "Interception already disabled"_s;
-        return;
-    }
-
     m_interceptionEnabled = enabled;
+    m_interceptRequests = interceptRequests && *interceptRequests;
 
     if (!m_interceptionEnabled)
         continuePendingResponses();
+    if (!m_interceptionEnabled || !m_interceptRequests)
+        continuePendingRequests();
 }
 
 void InspectorNetworkAgent::addInterception(ErrorString& errorString, const String& url, const bool* optionalCaseSensitive, const bool* optionalIsRegex, const String* networkStageString)
@@ -1112,19 +1135,128 @@ void InspectorNetworkAgent::interceptResponse(const ResourceResponse& response,
     m_frontendDispatcher->responseIntercepted(requestId, buildObjectForResourceResponse(response, nullptr));
 }
 
-void InspectorNetworkAgent::interceptContinue(ErrorString& errorString, const String& requestId)
-{
+bool InspectorNetworkAgent::interceptRequest(ResourceLoader& loader, Function<void(bool handled)>&& handler) {
+    if (!m_interceptionEnabled || !m_interceptRequests)
+        return false;
+    String requestId = IdentifiersFactory::requestId(loader.identifier());
+    auto pendingRequest = makeUnique<PendingInterceptRequest>();
+    pendingRequest->m_loader = &loader;
+    pendingRequest->m_callback = WTFMove(handler);
+    m_pendingInterceptRequests.set(requestId, WTFMove(pendingRequest));
+    m_frontendDispatcher->requestIntercepted(requestId, buildObjectForResourceRequest(loader.request()));
+    return true;
+}
+
+void InspectorNetworkAgent::interceptContinue(ErrorString& errorString, const String& requestId, const String* method, const JSON::Object* headers, const String* postData)
+{
+    auto pendingRequest = m_pendingInterceptRequests.take(requestId);
+    if (pendingRequest) {
+        ResourceLoader* loader = pendingRequest->m_loader.get();
+        if (!loader->identifier()) {
+            // Do not throw upon continue of canceled requests.
+            return;
+        }
+        // Safe to const cast at this point, we are only adjusting the method / headers / post.
+        ResourceRequest* request = const_cast<ResourceRequest*>(&loader->request());
+        if (method)
+            request->setHTTPMethod(*method);
+        if (headers) {
+            HTTPHeaderMap explicitHeaders;
+            for (auto& header : *headers) {
+                String headerValue;
+                if (header.value->asString(headerValue))
+                    explicitHeaders.add(header.key, headerValue);
+            }
+            request->setHTTPHeaderFields(WTFMove(explicitHeaders));
+        }
+        if (postData) {
+            Vector<uint8_t> buffer;
+            if (!base64Decode(*postData, buffer)) {
+                errorString = "Unable to decode given postData"_s;
+                return;
+            }
+            Ref<FormData> data = FormData::create(buffer);
+            request->setHTTPBody(WTFMove(data));
+        }
+        pendingRequest->m_callback(false);
+        return;
+    }
+
     auto pendingInterceptResponse = m_pendingInterceptResponses.take(requestId);
-    if (!pendingInterceptResponse) {
-        errorString = "Missing pending intercept response for given requestId"_s;
+    if (pendingInterceptResponse) {
+        pendingInterceptResponse->respondWithOriginalResponse();
         return;
     }
 
-    pendingInterceptResponse->respondWithOriginalResponse();
+    errorString = "Missing pending intercept response for given requestId"_s;
 }
 
-void InspectorNetworkAgent::interceptWithResponse(ErrorString& errorString, const String& requestId, const String& content, bool base64Encoded, const String* mimeType, const int* status, const String* statusText, const JSON::Object* headers)
+void InspectorNetworkAgent::interceptAsError(ErrorString& errorString, const String& requestId, const String& reason)
 {
+    auto pendingRequest = m_pendingInterceptRequests.take(requestId);
+    if (pendingRequest) {
+        ResourceLoader* loader = pendingRequest->m_loader.get();
+        if (!loader->identifier()) {
+            errorString = "Unable to abort request, it has already been processed"_s;
+            return;
+        }
+        ResourceError error(errorDomainWebKitInternal, 0, loader->url(), "Request intercepted"_s, ResourceError::Type::General);
+        if (reason == "AccessControl")
+            error = ResourceError(errorDomainWebKitInternal, 0, loader->url(), "Access denied"_s, ResourceError::Type::AccessControl);
+        else if (reason == "Cancellation")
+            error = ResourceError(errorDomainWebKitInternal, 0, loader->url(), "Request canceled"_s, ResourceError::Type::Cancellation);
+        else if (reason == "Timeout")
+            error = ResourceError(errorDomainWebKitInternal, 0, loader->url(), "Request timed out"_s, ResourceError::Type::Timeout);
+        loader->didFail(error);
+        pendingRequest->m_callback(true);
+        return;
+    }
+
+    errorString = "Missing pending intercept response for given requestId"_s;
+}
+
+void InspectorNetworkAgent::interceptWithResponse(ErrorString& errorString, const String& requestId, const String* content, const bool* base64Encoded, const String* mimeType, const int* status, const String* statusText, const JSON::Object* headers)
+{
+    auto pendingRequest = m_pendingInterceptRequests.take(requestId);
+    if (pendingRequest && status && statusText && mimeType && headers) {
+        RefPtr<ResourceLoader> loader = pendingRequest->m_loader.get();
+        if (!loader->identifier()) {
+            errorString = "Unable to fulfill request, it has already been processed"_s;
+            return;
+        }
+        RefPtr<SharedBuffer> data;
+        if (base64Encoded && *base64Encoded && content) {
+            Vector<uint8_t> buffer;
+            if (!base64Decode(*content, buffer)) {
+                errorString = "Unable to decode given content"_s;
+                return;
+            }
+            data = SharedBuffer::create(WTFMove(buffer));
+        } else if (content) {
+            data = SharedBuffer::create(content->utf8().data(), content->utf8().length());
+        }
+
+        ResourceResponse response(pendingRequest->m_loader->url(), *mimeType, data->size(), String());
+        response.setSource(ResourceResponse::Source::InspectorOverride);
+        response.setHTTPStatusCode(*status);
+        response.setHTTPStatusText(*statusText);
+        HTTPHeaderMap explicitHeaders;
+        for (auto& header : *headers) {
+            String headerValue;
+            if (header.value->asString(headerValue))
+                explicitHeaders.add(header.key, headerValue);
+        }
+        response.setHTTPHeaderFields(WTFMove(explicitHeaders));
+        response.setHTTPHeaderField(HTTPHeaderName::ContentType, response.mimeType());
+        loader->didReceiveResponse(response, [loader, data = data.releaseNonNull()]() mutable {
+            if (data->size())
+                loader->didReceiveBuffer(WTFMove(data), data->size(), DataPayloadWholeResource);
+            loader->didFinishLoading(NetworkLoadMetrics());
+        });
+        pendingRequest->m_callback(true);
+        return;
+    }
+
     auto pendingInterceptResponse = m_pendingInterceptResponses.take(requestId);
     if (!pendingInterceptResponse) {
         errorString = "Missing pending intercept response for given requestId"_s;
@@ -1152,20 +1284,26 @@ void InspectorNetworkAgent::interceptWithResponse(ErrorString& errorString, cons
     }
 
     RefPtr<SharedBuffer> overrideData;
-    if (base64Encoded) {
+    if (base64Encoded && *base64Encoded && content) {
         Vector<uint8_t> buffer;
-        if (!base64Decode(content, buffer)) {
+        if (!base64Decode(*content, buffer)) {
             errorString = "Unable to decode given content"_s;
             pendingInterceptResponse->respondWithOriginalResponse();
             return;
         }
         overrideData = SharedBuffer::create(WTFMove(buffer));
-    } else
-        overrideData = SharedBuffer::create(content.utf8().data(), content.utf8().length());
+    } else if (content) {
+        overrideData = SharedBuffer::create(content->utf8().data(), content->utf8().length());
+    }
 
     pendingInterceptResponse->respond(overrideResponse, overrideData);
 }
 
+void InspectorNetworkAgent::setEmulateOfflineState(ErrorString&, bool offline)
+{
+    platformStrategies()->loaderStrategy()->setEmulateOfflineState(offline);
+}
+
 bool InspectorNetworkAgent::shouldTreatAsText(const String& mimeType)
 {
     return startsWithLettersIgnoringASCIICase(mimeType, "text/")
@@ -1295,6 +1433,11 @@ void InspectorNetworkAgent::searchInRequest(ErrorString& errorString, const Stri
     results = ContentSearchUtilities::searchInTextByLines(resourceData->content(), query, caseSensitive, isRegex);
 }
 
+String InspectorNetworkAgent::createInitiatorIdentifierForInspectorNavigation(const String& referrer)
+{
+    return inspectorInitiatorPrefix() + referrer;
+}
+
 void InspectorNetworkAgent::mainFrameNavigated(DocumentLoader& loader)
 {
     m_resourcesData->clear(loaderIdentifier(&loader));
diff --git a/Source/WebCore/inspector/agents/InspectorNetworkAgent.h b/Source/WebCore/inspector/agents/InspectorNetworkAgent.h
index b038a1879c043aa17dae97425693f29be42e3258..d60716b837663004675ffd90bceede4c3a6e98c6 100644
--- a/Source/WebCore/inspector/agents/InspectorNetworkAgent.h
+++ b/Source/WebCore/inspector/agents/InspectorNetworkAgent.h
@@ -87,11 +87,13 @@ public:
     void loadResource(const String& frameId, const String& url, Ref<LoadResourceCallback>&&) final;
     void getSerializedCertificate(ErrorString&, const String& requestId, String* serializedCertificate) final;
     void resolveWebSocket(ErrorString&, const String& requestId, const String* objectGroup, RefPtr<Inspector::Protocol::Runtime::RemoteObject>&) final;
-    void setInterceptionEnabled(ErrorString&, bool enabled) final;
+    void setInterceptionEnabled(ErrorString&, bool enabled, const bool* interceptRequests) final;
     void addInterception(ErrorString&, const String& url, const bool* caseSensitive, const bool* isRegex, const String* networkStageString) final;
     void removeInterception(ErrorString&, const String& url, const bool* caseSensitive, const bool* isRegex, const String* networkStageString) final;
-    void interceptContinue(ErrorString&, const String& requestId) final;
-    void interceptWithResponse(ErrorString&, const String& requestId, const String& content, bool base64Encoded, const String* mimeType, const int* status, const String* statusText, const JSON::Object* headers) final;
+    void interceptContinue(ErrorString&, const String& requestId, const String* method, const JSON::Object* headers, const String* postData) final;
+    void interceptAsError(ErrorString&, const String& requestId, const String& reason) final;
+    void interceptWithResponse(ErrorString&, const String& requestId, const String* content, const bool* base64Encoded, const String* mimeType, const int* status, const String* statusText, const JSON::Object* headers) final;
+    void setEmulateOfflineState(ErrorString&, bool offline) final;
 
     // InspectorInstrumentation
     void willRecalculateStyle();
@@ -121,10 +123,13 @@ public:
     bool willInterceptRequest(const ResourceRequest&);
     bool shouldInterceptResponse(const ResourceResponse&);
     void interceptResponse(const ResourceResponse&, unsigned long identifier, CompletionHandler<void(const ResourceResponse&, RefPtr<SharedBuffer>)>&&);
+    bool interceptRequest(ResourceLoader& loader, Function<void(bool handled)>&&);
 
     void searchOtherRequests(const JSC::Yarr::RegularExpression&, RefPtr<JSON::ArrayOf<Inspector::Protocol::Page::SearchResult>>&);
     void searchInRequest(ErrorString&, const String& requestId, const String& query, bool caseSensitive, bool isRegex, RefPtr<JSON::ArrayOf<Inspector::Protocol::GenericTypes::SearchMatch>>&);
 
+    static String createInitiatorIdentifierForInspectorNavigation(const String& referrer);
+
 protected:
     InspectorNetworkAgent(WebAgentContext&);
 
@@ -141,6 +146,7 @@ private:
     void willSendRequest(unsigned long identifier, DocumentLoader*, ResourceRequest&, const ResourceResponse& redirectResponse, InspectorPageAgent::ResourceType);
 
     bool shouldIntercept(URL);
+    void continuePendingRequests();
     void continuePendingResponses();
 
     WebSocket* webSocketForRequestId(const String& requestId);
@@ -191,6 +197,15 @@ private:
         bool m_responded { false };
     };
 
+    class PendingInterceptRequest {
+        WTF_MAKE_NONCOPYABLE(PendingInterceptRequest);
+        WTF_MAKE_FAST_ALLOCATED;
+    public:
+        PendingInterceptRequest() = default;
+        RefPtr<ResourceLoader> m_loader;
+        CompletionHandler<void(bool handled)> m_callback;
+    };
+
     std::unique_ptr<Inspector::NetworkFrontendDispatcher> m_frontendDispatcher;
     RefPtr<Inspector::NetworkBackendDispatcher> m_backendDispatcher;
     Inspector::InjectedScriptManager& m_injectedScriptManager;
@@ -214,6 +229,7 @@ private:
     };
     Vector<Intercept> m_intercepts;
     HashMap<String, std::unique_ptr<PendingInterceptResponse>> m_pendingInterceptResponses;
+    HashMap<String, std::unique_ptr<PendingInterceptRequest>> m_pendingInterceptRequests;
 
     // FIXME: InspectorNetworkAgent should not be aware of style recalculation.
     RefPtr<Inspector::Protocol::Network::Initiator> m_styleRecalculationInitiator;
@@ -222,6 +238,7 @@ private:
     bool m_enabled { false };
     bool m_loadingXHRSynchronously { false };
     bool m_interceptionEnabled { false };
+    bool m_interceptRequests { false };
 };
 
 } // namespace WebCore
diff --git a/Source/WebCore/inspector/agents/InspectorPageAgent.cpp b/Source/WebCore/inspector/agents/InspectorPageAgent.cpp
index d678cddbd20a1a2b410a8ebbb17f5f63f0fc620d..1401a479745c2f90700f80707c1019c91601d986 100644
--- a/Source/WebCore/inspector/agents/InspectorPageAgent.cpp
+++ b/Source/WebCore/inspector/agents/InspectorPageAgent.cpp
@@ -32,6 +32,8 @@
 #include "config.h"
 #include "InspectorPageAgent.h"
 
+#include "AXObjectCache.h"
+#include "BackForwardController.h"
 #include "CachedResource.h"
 #include "CachedResourceLoader.h"
 #include "Cookie.h"
@@ -40,12 +42,15 @@
 #include "DOMWrapperWorld.h"
 #include "Document.h"
 #include "DocumentLoader.h"
+#include "FocusController.h"
 #include "Frame.h"
 #include "FrameLoadRequest.h"
 #include "FrameLoader.h"
+#include "FrameLoaderClient.h"
 #include "FrameSnapshotting.h"
 #include "FrameView.h"
 #include "HTMLFrameOwnerElement.h"
+#include "HTMLInputElement.h"
 #include "HTMLNames.h"
 #include "ImageBuffer.h"
 #include "InspectorClient.h"
@@ -56,19 +61,29 @@
 #include "MIMETypeRegistry.h"
 #include "MemoryCache.h"
 #include "Page.h"
+#include "PageRuntimeAgent.h"
 #include "RenderObject.h"
 #include "RenderTheme.h"
+#include "RuntimeEnabledFeatures.h"
 #include "ScriptController.h"
 #include "ScriptSourceCode.h"
+#include "ScriptState.h"
 #include "SecurityOrigin.h"
 #include "Settings.h"
 #include "StyleScope.h"
 #include "TextEncoding.h"
+#include "TypingCommand.h"
 #include "UserGestureIndicator.h"
 #include <JavaScriptCore/ContentSearchUtilities.h>
 #include <JavaScriptCore/IdentifiersFactory.h>
+#include <JavaScriptCore/InjectedScriptManager.h>
 #include <JavaScriptCore/RegularExpression.h>
+#include <platform/ProcessIdentifier.h>
+#include <wtf/DateMath.h>
 #include <wtf/ListHashSet.h>
+#include <wtf/NeverDestroyed.h>
+#include <wtf/Ref.h>
+#include <wtf/RefPtr.h>
 #include <wtf/Stopwatch.h>
 #include <wtf/text/Base64.h>
 #include <wtf/text/StringBuilder.h>
@@ -81,7 +96,6 @@
 #include "LegacyWebArchive.h"
 #endif
 
-
 namespace WebCore {
 
 using namespace Inspector;
@@ -100,6 +114,11 @@ using namespace Inspector;
     macro(WebRTCEncryptionEnabled) \
     macro(WebSecurityEnabled)
 
+static HashMap<String, Ref<DOMWrapperWorld>>& createdUserWorlds() {
+    static NeverDestroyed<HashMap<String, Ref<DOMWrapperWorld>>> nameToWorld;
+    return nameToWorld;
+}
+
 static bool decodeBuffer(const char* buffer, unsigned size, const String& textEncodingName, String* result)
 {
     if (buffer) {
@@ -340,6 +359,7 @@ InspectorPageAgent::InspectorPageAgent(PageAgentContext& context, InspectorClien
     , m_frontendDispatcher(makeUnique<Inspector::PageFrontendDispatcher>(context.frontendRouter))
     , m_backendDispatcher(Inspector::PageBackendDispatcher::create(context.backendDispatcher, this))
     , m_inspectedPage(context.inspectedPage)
+    , m_injectedScriptManager(context.injectedScriptManager)
     , m_client(client)
     , m_overlay(overlay)
 {
@@ -373,11 +393,20 @@ void InspectorPageAgent::enable(ErrorString& errorString)
 #if HAVE(OS_DARK_MODE_SUPPORT)
     defaultAppearanceDidChange(m_inspectedPage.defaultUseDarkAppearance());
 #endif
+
+    if (!createdUserWorlds().isEmpty()) {
+        Vector<DOMWrapperWorld*> worlds;
+        for (const auto& world : createdUserWorlds().values())
+            worlds.append(world.ptr());
+        ensureUserWorldsExistInAllFrames(worlds);
+    }
 }
 
 void InspectorPageAgent::disable(ErrorString&)
 {
     m_instrumentingAgents.setInspectorPageAgent(nullptr);
+    m_interceptFileChooserDialog = false;
+    m_bypassCSP = false;
 
     ErrorString unused;
     setShowPaintRects(unused, false);
@@ -415,14 +444,36 @@ void InspectorPageAgent::reload(ErrorString&, const bool* optionalReloadFromOrig
     m_inspectedPage.mainFrame().loader().reload(reloadOptions);
 }
 
-void InspectorPageAgent::navigate(ErrorString&, const String& url)
+void InspectorPageAgent::goBack(ErrorString& errorString)
+{
+    if (!m_inspectedPage.backForward().goBack())
+        errorString = "Failed to go back"_s;
+}
+
+void InspectorPageAgent::goForward(ErrorString& errorString)
+{
+    if (!m_inspectedPage.backForward().goForward())
+        errorString = "Failed to go forward"_s;
+}
+
+void InspectorPageAgent::navigate(ErrorString& errorString, const String& url, const String* frameId, const String* referrer)
 {
     UserGestureIndicator indicator { ProcessingUserGesture };
-    Frame& frame = m_inspectedPage.mainFrame();
+    Frame* frame = frameId ? assertFrame(errorString, *frameId) : &m_inspectedPage.mainFrame();
+    if (!frame)
+        return;
+
+    ResourceRequest resourceRequest { frame->document()->completeURL(url) };
 
-    ResourceRequest resourceRequest { frame.document()->completeURL(url) };
-    FrameLoadRequest frameLoadRequest { *frame.document(), frame.document()->securityOrigin(), resourceRequest, "_self"_s, LockHistory::No, LockBackForwardList::No, MaybeSendReferrer, AllowNavigationToInvalidURL::No, NewFrameOpenerPolicy::Allow, ShouldOpenExternalURLsPolicy::ShouldNotAllow, InitiatedByMainFrame::Unknown };
-    frame.loader().changeLocation(WTFMove(frameLoadRequest));
+    if (!resourceRequest.url().isValid()) {
+        errorString = "Cannot navigate to invalid URL"_s;
+        return;
+    }
+
+    if (referrer)
+        resourceRequest.setInitiatorIdentifier(InspectorNetworkAgent::createInitiatorIdentifierForInspectorNavigation(*referrer));
+    FrameLoadRequest frameLoadRequest { *frame->document(), frame->document()->securityOrigin(), resourceRequest, "_self"_s, LockHistory::No, LockBackForwardList::No, MaybeSendReferrer, AllowNavigationToInvalidURL::No, NewFrameOpenerPolicy::Allow, ShouldOpenExternalURLsPolicy::ShouldNotAllow, InitiatedByMainFrame::Unknown };
+    frame->loader().changeLocation(WTFMove(frameLoadRequest));
 }
 
 void InspectorPageAgent::overrideUserAgent(ErrorString&, const String* value)
@@ -683,15 +734,16 @@ void InspectorPageAgent::setShowPaintRects(ErrorString&, bool show)
     m_overlay->setShowPaintRects(show);
 }
 
-void InspectorPageAgent::domContentEventFired()
+void InspectorPageAgent::domContentEventFired(Frame& frame)
 {
-    m_isFirstLayoutAfterOnLoad = true;
-    m_frontendDispatcher->domContentEventFired(timestamp());
+    if (frame.isMainFrame())
+        m_isFirstLayoutAfterOnLoad = true;
+    m_frontendDispatcher->domContentEventFired(timestamp(), frameId(&frame));
 }
 
-void InspectorPageAgent::loadEventFired()
+void InspectorPageAgent::loadEventFired(Frame& frame)
 {
-    m_frontendDispatcher->loadEventFired(timestamp());
+    m_frontendDispatcher->loadEventFired(timestamp(), frameId(&frame));
 }
 
 void InspectorPageAgent::frameNavigated(Frame& frame)
@@ -699,13 +751,18 @@ void InspectorPageAgent::frameNavigated(Frame& frame)
     m_frontendDispatcher->frameNavigated(buildObjectForFrame(&frame));
 }
 
+static String globalIDForFrame(Frame& frame)
+{
+    return makeString(Process::identifier().toUInt64(), ".", frame.loader().client().frameID()->toUInt64());
+}
+
 void InspectorPageAgent::frameDetached(Frame& frame)
 {
-    auto identifier = m_frameToIdentifier.take(&frame);
-    if (identifier.isNull())
+    String identifier = globalIDForFrame(frame);
+    if (!m_identifierToFrame.take(identifier))
         return;
+
     m_frontendDispatcher->frameDetached(identifier);
-    m_identifierToFrame.remove(identifier);
 }
 
 Frame* InspectorPageAgent::frameForId(const String& frameId)
@@ -717,20 +774,18 @@ String InspectorPageAgent::frameId(Frame* frame)
 {
     if (!frame)
         return emptyString();
-    return m_frameToIdentifier.ensure(frame, [this, frame] {
-        auto identifier = IdentifiersFactory::createIdentifier();
-        m_identifierToFrame.set(identifier, frame);
-        return identifier;
-    }).iterator->value;
+
+    String identifier = globalIDForFrame(*frame);
+    m_identifierToFrame.set(identifier, frame);
+    return identifier;
 }
 
 String InspectorPageAgent::loaderId(DocumentLoader* loader)
 {
     if (!loader)
         return emptyString();
-    return m_loaderToIdentifier.ensure(loader, [] {
-        return IdentifiersFactory::createIdentifier();
-    }).iterator->value;
+
+    return String::number(loader->loaderIDForInspector());
 }
 
 Frame* InspectorPageAgent::assertFrame(ErrorString& errorString, const String& frameId)
@@ -741,11 +796,6 @@ Frame* InspectorPageAgent::assertFrame(ErrorString& errorString, const String& f
     return frame;
 }
 
-void InspectorPageAgent::loaderDetachedFromFrame(DocumentLoader& loader)
-{
-    m_loaderToIdentifier.remove(&loader);
-}
-
 void InspectorPageAgent::frameStartedLoading(Frame& frame)
 {
     m_frontendDispatcher->frameStartedLoading(frameId(&frame));
@@ -766,6 +816,12 @@ void InspectorPageAgent::frameClearedScheduledNavigation(Frame& frame)
     m_frontendDispatcher->frameClearedScheduledNavigation(frameId(&frame));
 }
 
+void InspectorPageAgent::didNavigateWithinPage(Frame& frame)
+{
+    String url = frame.document()->url().string();
+    m_frontendDispatcher->navigatedWithinDocument(frameId(&frame), url);
+}
+
 void InspectorPageAgent::defaultAppearanceDidChange(bool useDarkAppearance)
 {
     m_frontendDispatcher->defaultAppearanceDidChange(useDarkAppearance ? Inspector::Protocol::Page::Appearance::Dark : Inspector::Protocol::Page::Appearance::Light);
@@ -823,6 +879,38 @@ void InspectorPageAgent::didRecalculateStyle()
     m_overlay->update();
 }
 
+void InspectorPageAgent::runOpenPanel(HTMLInputElement* element, bool* intercept)
+{
+    if (m_interceptFileChooserDialog) {
+        *intercept = true;
+    } else {
+        return;
+    }
+    Document& document = element->document();
+    auto* frame =  document.frame();
+    if (!frame)
+        return;
+
+    auto& state = *mainWorldExecState(frame);
+    auto injectedScript = m_injectedScriptManager.injectedScriptFor(&state);
+    if (injectedScript.hasNoValue())
+        return;
+
+    m_frontendDispatcher->fileChooserOpened(frameId(frame), injectedScript.wrapObject(InspectorDOMAgent::nodeAsScriptValue(state, element), WTF::String()));
+}
+
+void InspectorPageAgent::frameAttached(Frame& frame)
+{
+    Frame* parent = frame.tree().parent();
+    String parentFrameId = frameId(parent);
+    m_frontendDispatcher->frameAttached(frameId(&frame), parent ? &parentFrameId : nullptr);
+}
+
+bool InspectorPageAgent::shouldBypassCSP()
+{
+    return m_bypassCSP;
+}
+
 Ref<Inspector::Protocol::Page::Frame> InspectorPageAgent::buildObjectForFrame(Frame* frame)
 {
     ASSERT_ARG(frame, frame);
@@ -966,6 +1054,29 @@ void InspectorPageAgent::snapshotRect(ErrorString& errorString, int x, int y, in
     *outDataURL = snapshot->toDataURL("image/png"_s, WTF::nullopt, PreserveResolution::Yes);
 }
 
+void InspectorPageAgent::setTimeZone(ErrorString& errorString, const String* timeZone)
+{
+    if (!timeZone) {
+        WTF::setTimeZoneForAutomation(String());
+        return;
+    }
+    bool success = WTF::setTimeZoneForAutomation(*timeZone);
+    if (!success)
+        errorString = "Invalid time zone " + *timeZone;
+}
+
+void InspectorPageAgent::setTouchEmulationEnabled(ErrorString& errorString, bool enabled)
+{
+#if ENABLE(TOUCH_EVENTS)
+    RuntimeEnabledFeatures::sharedFeatures().setTouchEventsEnabled(enabled);
+    UNUSED_PARAM(errorString);
+#else
+    UNUSED_PARAM(enabled);
+    errorString = "Not supported"_s;
+#endif
+}
+
+
 void InspectorPageAgent::archive(ErrorString& errorString, String* data)
 {
 #if ENABLE(WEB_ARCHIVE) && USE(CF)
@@ -983,4 +1094,529 @@ void InspectorPageAgent::archive(ErrorString& errorString, String* data)
 #endif
 }
 
+void InspectorPageAgent::insertText(ErrorString&, const String& text)
+{
+    UserGestureIndicator indicator { ProcessingUserGesture };
+    Document* focusedDocument = m_inspectedPage.focusController().focusedOrMainFrame().document();
+    TypingCommand::insertText(*focusedDocument, text, 0);
+}
+
+static String roleFromObject(RefPtr<AXCoreObject> axObject)
+{
+    String computedRoleString = axObject->computedRoleString();
+    if (!computedRoleString.isEmpty())
+        return computedRoleString;
+    AccessibilityRole role = axObject->roleValue();
+    switch(role) {
+        case AccessibilityRole::Annotation:
+            return "Annotation";
+        case AccessibilityRole::Application:
+            return "Application";
+        case AccessibilityRole::ApplicationAlert:
+            return "ApplicationAlert";
+        case AccessibilityRole::ApplicationAlertDialog:
+            return "ApplicationAlertDialog";
+        case AccessibilityRole::ApplicationDialog:
+            return "ApplicationDialog";
+        case AccessibilityRole::ApplicationGroup:
+            return "ApplicationGroup";
+        case AccessibilityRole::ApplicationLog:
+            return "ApplicationLog";
+        case AccessibilityRole::ApplicationMarquee:
+            return "ApplicationMarquee";
+        case AccessibilityRole::ApplicationStatus:
+            return "ApplicationStatus";
+        case AccessibilityRole::ApplicationTextGroup:
+            return "ApplicationTextGroup";
+        case AccessibilityRole::ApplicationTimer:
+            return "ApplicationTimer";
+        case AccessibilityRole::Audio:
+            return "Audio";
+        case AccessibilityRole::Blockquote:
+            return "Blockquote";
+        case AccessibilityRole::Browser:
+            return "Browser";
+        case AccessibilityRole::BusyIndicator:
+            return "BusyIndicator";
+        case AccessibilityRole::Button:
+            return "Button";
+        case AccessibilityRole::Canvas:
+            return "Canvas";
+        case AccessibilityRole::Caption:
+            return "Caption";
+        case AccessibilityRole::Cell:
+            return "Cell";
+        case AccessibilityRole::CheckBox:
+            return "CheckBox";
+        case AccessibilityRole::ColorWell:
+            return "ColorWell";
+        case AccessibilityRole::Column:
+            return "Column";
+        case AccessibilityRole::ColumnHeader:
+            return "ColumnHeader";
+        case AccessibilityRole::ComboBox:
+            return "ComboBox";
+        case AccessibilityRole::Definition:
+            return "Definition";
+        case AccessibilityRole::Deletion:
+            return "Deletion";
+        case AccessibilityRole::DescriptionList:
+            return "DescriptionList";
+        case AccessibilityRole::DescriptionListTerm:
+            return "DescriptionListTerm";
+        case AccessibilityRole::DescriptionListDetail:
+            return "DescriptionListDetail";
+        case AccessibilityRole::Details:
+            return "Details";
+        case AccessibilityRole::Directory:
+            return "Directory";
+        case AccessibilityRole::DisclosureTriangle:
+            return "DisclosureTriangle";
+        case AccessibilityRole::Div:
+            return "Div";
+        case AccessibilityRole::Document:
+            return "Document";
+        case AccessibilityRole::DocumentArticle:
+            return "DocumentArticle";
+        case AccessibilityRole::DocumentMath:
+            return "DocumentMath";
+        case AccessibilityRole::DocumentNote:
+            return "DocumentNote";
+        case AccessibilityRole::Drawer:
+            return "Drawer";
+        case AccessibilityRole::EditableText:
+            return "EditableText";
+        case AccessibilityRole::Feed:
+            return "Feed";
+        case AccessibilityRole::Figure:
+            return "Figure";
+        case AccessibilityRole::Footer:
+            return "Footer";
+        case AccessibilityRole::Footnote:
+            return "Footnote";
+        case AccessibilityRole::Form:
+            return "Form";
+        case AccessibilityRole::GraphicsDocument:
+            return "GraphicsDocument";
+        case AccessibilityRole::GraphicsObject:
+            return "GraphicsObject";
+        case AccessibilityRole::GraphicsSymbol:
+            return "GraphicsSymbol";
+        case AccessibilityRole::Grid:
+            return "Grid";
+        case AccessibilityRole::GridCell:
+            return "GridCell";
+        case AccessibilityRole::Group:
+            return "Group";
+        case AccessibilityRole::GrowArea:
+            return "GrowArea";
+        case AccessibilityRole::Heading:
+            return "Heading";
+        case AccessibilityRole::HelpTag:
+            return "HelpTag";
+        case AccessibilityRole::HorizontalRule:
+            return "HorizontalRule";
+        case AccessibilityRole::Ignored:
+            return "Ignored";
+        case AccessibilityRole::Inline:
+            return "Inline";
+        case AccessibilityRole::Image:
+            return "Image";
+        case AccessibilityRole::ImageMap:
+            return "ImageMap";
+        case AccessibilityRole::ImageMapLink:
+            return "ImageMapLink";
+        case AccessibilityRole::Incrementor:
+            return "Incrementor";
+        case AccessibilityRole::Insertion:
+            return "Insertion";
+        case AccessibilityRole::Label:
+            return "Label";
+        case AccessibilityRole::LandmarkBanner:
+            return "LandmarkBanner";
+        case AccessibilityRole::LandmarkComplementary:
+            return "LandmarkComplementary";
+        case AccessibilityRole::LandmarkContentInfo:
+            return "LandmarkContentInfo";
+        case AccessibilityRole::LandmarkDocRegion:
+            return "LandmarkDocRegion";
+        case AccessibilityRole::LandmarkMain:
+            return "LandmarkMain";
+        case AccessibilityRole::LandmarkNavigation:
+            return "LandmarkNavigation";
+        case AccessibilityRole::LandmarkRegion:
+            return "LandmarkRegion";
+        case AccessibilityRole::LandmarkSearch:
+            return "LandmarkSearch";
+        case AccessibilityRole::Legend:
+            return "Legend";
+        case AccessibilityRole::Link:
+            return "Link";
+        case AccessibilityRole::List:
+            return "List";
+        case AccessibilityRole::ListBox:
+            return "ListBox";
+        case AccessibilityRole::ListBoxOption:
+            return "ListBoxOption";
+        case AccessibilityRole::ListItem:
+            return "ListItem";
+        case AccessibilityRole::ListMarker:
+            return "ListMarker";
+        case AccessibilityRole::Mark:
+            return "Mark";
+        case AccessibilityRole::MathElement:
+            return "MathElement";
+        case AccessibilityRole::Matte:
+            return "Matte";
+        case AccessibilityRole::Menu:
+            return "Menu";
+        case AccessibilityRole::MenuBar:
+            return "MenuBar";
+        case AccessibilityRole::MenuButton:
+            return "MenuButton";
+        case AccessibilityRole::MenuItem:
+            return "MenuItem";
+        case AccessibilityRole::MenuItemCheckbox:
+            return "MenuItemCheckbox";
+        case AccessibilityRole::MenuItemRadio:
+            return "MenuItemRadio";
+        case AccessibilityRole::MenuListPopup:
+            return "MenuListPopup";
+        case AccessibilityRole::MenuListOption:
+            return "MenuListOption";
+        case AccessibilityRole::Meter:
+            return "Meter";
+        case AccessibilityRole::Outline:
+            return "Outline";
+        case AccessibilityRole::Paragraph:
+            return "Paragraph";
+        case AccessibilityRole::PopUpButton:
+            return "PopUpButton";
+        case AccessibilityRole::Pre:
+            return "Pre";
+        case AccessibilityRole::Presentational:
+            return "Presentational";
+        case AccessibilityRole::ProgressIndicator:
+            return "ProgressIndicator";
+        case AccessibilityRole::RadioButton:
+            return "RadioButton";
+        case AccessibilityRole::RadioGroup:
+            return "RadioGroup";
+        case AccessibilityRole::RowHeader:
+            return "RowHeader";
+        case AccessibilityRole::Row:
+            return "Row";
+        case AccessibilityRole::RowGroup:
+            return "RowGroup";
+        case AccessibilityRole::RubyBase:
+            return "RubyBase";
+        case AccessibilityRole::RubyBlock:
+            return "RubyBlock";
+        case AccessibilityRole::RubyInline:
+            return "RubyInline";
+        case AccessibilityRole::RubyRun:
+            return "RubyRun";
+        case AccessibilityRole::RubyText:
+            return "RubyText";
+        case AccessibilityRole::Ruler:
+            return "Ruler";
+        case AccessibilityRole::RulerMarker:
+            return "RulerMarker";
+        case AccessibilityRole::ScrollArea:
+            return "ScrollArea";
+        case AccessibilityRole::ScrollBar:
+            return "ScrollBar";
+        case AccessibilityRole::SearchField:
+            return "SearchField";
+        case AccessibilityRole::Sheet:
+            return "Sheet";
+        case AccessibilityRole::Slider:
+            return "Slider";
+        case AccessibilityRole::SliderThumb:
+            return "SliderThumb";
+        case AccessibilityRole::SpinButton:
+            return "SpinButton";
+        case AccessibilityRole::SpinButtonPart:
+            return "SpinButtonPart";
+        case AccessibilityRole::SplitGroup:
+            return "SplitGroup";
+        case AccessibilityRole::Splitter:
+            return "Splitter";
+        case AccessibilityRole::StaticText:
+            return "StaticText";
+        case AccessibilityRole::Subscript:
+            return "Subscript";
+        case AccessibilityRole::Summary:
+            return "Summary";
+        case AccessibilityRole::Superscript:
+            return "Superscript";
+        case AccessibilityRole::Switch:
+            return "Switch";
+        case AccessibilityRole::SystemWide:
+            return "SystemWide";
+        case AccessibilityRole::SVGRoot:
+            return "SVGRoot";
+        case AccessibilityRole::SVGText:
+            return "SVGText";
+        case AccessibilityRole::SVGTSpan:
+            return "SVGTSpan";
+        case AccessibilityRole::SVGTextPath:
+            return "SVGTextPath";
+        case AccessibilityRole::TabGroup:
+            return "TabGroup";
+        case AccessibilityRole::TabList:
+            return "TabList";
+        case AccessibilityRole::TabPanel:
+            return "TabPanel";
+        case AccessibilityRole::Tab:
+            return "Tab";
+        case AccessibilityRole::Table:
+            return "Table";
+        case AccessibilityRole::TableHeaderContainer:
+            return "TableHeaderContainer";
+        case AccessibilityRole::TextArea:
+            return "TextArea";
+        case AccessibilityRole::TextGroup:
+            return "TextGroup";
+        case AccessibilityRole::Term:
+            return "Term";
+        case AccessibilityRole::Time:
+            return "Time";
+        case AccessibilityRole::Tree:
+            return "Tree";
+        case AccessibilityRole::TreeGrid:
+            return "TreeGrid";
+        case AccessibilityRole::TreeItem:
+            return "TreeItem";
+        case AccessibilityRole::TextField:
+            return "TextField";
+        case AccessibilityRole::ToggleButton:
+            return "ToggleButton";
+        case AccessibilityRole::Toolbar:
+            return "Toolbar";
+        case AccessibilityRole::Unknown:
+            return "Unknown";
+        case AccessibilityRole::UserInterfaceTooltip:
+            return "UserInterfaceTooltip";
+        case AccessibilityRole::ValueIndicator:
+            return "ValueIndicator";
+        case AccessibilityRole::Video:
+            return "Video";
+        case AccessibilityRole::WebApplication:
+            return "WebApplication";
+        case AccessibilityRole::WebArea:
+            return "WebArea";
+        case AccessibilityRole::WebCoreLink:
+            return "WebCoreLink";
+        case AccessibilityRole::Window:
+            return "Window";
+    };
+    return "Unknown";
+}
+
+static RefPtr<Inspector::Protocol::Page::AXNode> snapshotForAXObject(RefPtr<AXCoreObject> axObject, Node* nodeToFind)
+{
+    auto axNode = Inspector::Protocol::Page::AXNode::create()
+        .setRole(roleFromObject(axObject))
+        .release();
+
+    if (!axObject->computedLabel().isEmpty())
+        axNode->setName(axObject->computedLabel());
+    if (!axObject->stringValue().isEmpty())
+        axNode->setValue(JSON::Value::create(axObject->stringValue()));
+    if (!axObject->accessibilityDescription().isEmpty())
+        axNode->setDescription(axObject->accessibilityDescription());
+    if (!axObject->keyShortcutsValue().isEmpty())
+        axNode->setKeyshortcuts(axObject->keyShortcutsValue());
+    if (!axObject->valueDescription().isEmpty())
+        axNode->setValuetext(axObject->valueDescription());
+    if (!axObject->roleDescription().isEmpty())
+        axNode->setRoledescription(axObject->roleDescription());
+    if (!axObject->isEnabled())
+        axNode->setDisabled(!axObject->isEnabled());
+    if (axObject->supportsExpanded())
+        axNode->setExpanded(axObject->isExpanded());
+    if (axObject->isFocused())
+        axNode->setFocused(axObject->isFocused());
+    if (axObject->isModalNode())
+        axNode->setModal(axObject->isModalNode());
+    bool multiline = axObject->ariaIsMultiline() || axObject->roleValue() == AccessibilityRole::TextArea;
+    if (multiline)
+        axNode->setMultiline(multiline);
+    if (axObject->isMultiSelectable())
+        axNode->setMultiselectable(axObject->isMultiSelectable());
+    if (axObject->supportsReadOnly() && !axObject->canSetValueAttribute() && axObject->isEnabled())
+        axNode->setReadonly(true);
+    if (axObject->supportsRequiredAttribute())
+        axNode->setRequired(axObject->isRequired());
+    if (axObject->isSelected())
+        axNode->setSelected(axObject->isSelected());
+    if (axObject->supportsChecked()) {
+        AccessibilityButtonState checkedState = axObject->checkboxOrRadioValue();
+        switch (checkedState) {
+            case AccessibilityButtonState::On:
+                axNode->setChecked(Inspector::Protocol::Page::AXNode::Checked::True);
+                break;
+            case AccessibilityButtonState::Off:
+                axNode->setChecked(Inspector::Protocol::Page::AXNode::Checked::False);
+                break;
+            case AccessibilityButtonState::Mixed:
+                axNode->setChecked(Inspector::Protocol::Page::AXNode::Checked::Mixed);
+                break;
+        }
+    }
+    if (axObject->supportsPressed()) {
+        AccessibilityButtonState checkedState = axObject->checkboxOrRadioValue();
+        switch (checkedState) {
+            case AccessibilityButtonState::On:
+                axNode->setPressed(Inspector::Protocol::Page::AXNode::Pressed::True);
+                break;
+            case AccessibilityButtonState::Off:
+                axNode->setPressed(Inspector::Protocol::Page::AXNode::Pressed::False);
+                break;
+            case AccessibilityButtonState::Mixed:
+                axNode->setPressed(Inspector::Protocol::Page::AXNode::Pressed::Mixed);
+                break;
+        }
+    }
+    unsigned level = axObject->hierarchicalLevel() ? axObject->hierarchicalLevel() : axObject->headingLevel();
+    if (level)
+        axNode->setLevel(level);
+    if (axObject->minValueForRange() != 0)
+        axNode->setValuemin(axObject->minValueForRange());
+    if (axObject->maxValueForRange() != 0)
+        axNode->setValuemax(axObject->maxValueForRange());
+    if (axObject->supportsAutoComplete())
+        axNode->setAutocomplete(axObject->autoCompleteValue());
+    if (axObject->hasPopup())
+        axNode->setHaspopup(axObject->popupValue());
+
+    String invalidValue = axObject->invalidStatus();
+    if (invalidValue != "false") {
+        if (invalidValue == "grammar")
+            axNode->setInvalid(Inspector::Protocol::Page::AXNode::Invalid::Grammar);
+        else if (invalidValue == "spelling")
+            axNode->setInvalid(Inspector::Protocol::Page::AXNode::Invalid::Spelling);
+        else // Future versions of ARIA may allow additional truthy values. Ex. format, order, or size.
+            axNode->setInvalid(Inspector::Protocol::Page::AXNode::Invalid::True);
+    }
+    switch (axObject->orientation()) {
+        case AccessibilityOrientation::Undefined:
+            break;
+        case AccessibilityOrientation::Vertical:
+            axNode->setOrientation("vertical"_s);
+            break;
+        case AccessibilityOrientation::Horizontal:
+            axNode->setOrientation("horizontal"_s);
+            break;
+    }
+
+    if (axObject->isKeyboardFocusable())
+        axNode->setFocusable(axObject->isKeyboardFocusable());
+
+    if (nodeToFind && axObject->node() == nodeToFind)
+        axNode->setFound(true);
+
+    if (axObject->hasChildren()) {
+        RefPtr<JSON::ArrayOf<Inspector::Protocol::Page::AXNode>> children = JSON::ArrayOf<Inspector::Protocol::Page::AXNode>::create();
+        for (auto& childObject : axObject->children())
+            children->addItem(snapshotForAXObject(childObject, nodeToFind));
+        axNode->setChildren(children);
+    }
+    return axNode;
+}
+
+
+void InspectorPageAgent::accessibilitySnapshot(ErrorString& errorString, const String* objectId, RefPtr<Inspector::Protocol::Page::AXNode>& out_axNode)
+{
+    if (!WebCore::AXObjectCache::accessibilityEnabled())
+        WebCore::AXObjectCache::enableAccessibility();
+    auto document = makeRefPtr(m_inspectedPage.mainFrame().document());
+    if (!document) {
+        errorString = "No document for main frame"_s;
+        return;
+    }
+    AXObjectCache* axObjectCache = document->axObjectCache();
+    if (!axObjectCache) {
+        errorString = "No AXObjectCache for main document"_s;
+        return;
+    }
+    AXCoreObject* axObject = axObjectCache->rootObject();
+    if (!axObject) {
+        errorString = "No AXObject for main document"_s;
+        return;
+    }
+
+    Node* node = nullptr;
+    if (objectId) {
+        InspectorDOMAgent* domAgent = m_instrumentingAgents.inspectorDOMAgent();
+        ASSERT(domAgent);
+        node = domAgent->nodeForObjectId(*objectId);
+        if (!node) {
+            errorString = "No Node for objectId"_s;
+            return;
+        }
+    }
+
+    out_axNode = snapshotForAXObject(makeRefPtr(axObject), node);
+}
+
+void InspectorPageAgent::setInterceptFileChooserDialog(ErrorString&, bool enabled)
+{
+    m_interceptFileChooserDialog = enabled;
+}
+
+void InspectorPageAgent::setDefaultBackgroundColorOverride(ErrorString& errorString, const JSON::Object* color)
+{
+    FrameView* view = m_inspectedPage.mainFrame().view();
+    if (!view) {
+        errorString = "Internal error: No frame view to set color two"_s;
+        return;
+    }
+    if (!color) {
+        view->updateBackgroundRecursively(Optional<Color>());
+        return;
+    }
+    view->updateBackgroundRecursively(InspectorDOMAgent::parseColor(color));
+}
+
+void InspectorPageAgent::createUserWorld(ErrorString& errorString, const String& name)
+{
+    if (createdUserWorlds().contains(name)) {
+        errorString = "World with the given name already exists"_s;
+        return;
+    }
+
+    Ref<DOMWrapperWorld> world = ScriptController::createWorld(name, ScriptController::WorldType::User);
+    ensureUserWorldsExistInAllFrames({world.ptr()});
+    createdUserWorlds().set(name, WTFMove(world));
+}
+
+void InspectorPageAgent::ensureUserWorldsExistInAllFrames(const Vector<DOMWrapperWorld*>& worlds)
+{
+    for (Frame* frame = &m_inspectedPage.mainFrame(); frame; frame = frame->tree().traverseNext()) {
+        for (auto* world : worlds)
+            frame->windowProxy().jsWindowProxy(*world)->window();
+    }
+}
+
+void InspectorPageAgent::setBypassCSP(ErrorString&, bool enabled)
+{
+    m_bypassCSP = enabled;
+}
+
+void InspectorPageAgent::crash(ErrorString&)
+{
+    CRASH();
+}
+
+void InspectorPageAgent::setScreenSizeOverride(ErrorString&, int width, int height)
+{
+    Optional<FloatSize> size;
+    if (width && height)
+        size = FloatSize(width, height);
+    m_inspectedPage.setOverrideScreenSize(size);
+}
+
+
 } // namespace WebCore
diff --git a/Source/WebCore/inspector/agents/InspectorPageAgent.h b/Source/WebCore/inspector/agents/InspectorPageAgent.h
index 110173dbbfe819226b6c4caa0f65a5dee8c39f2b..f59486b7e1635ceaa67f3fe5968e8e0e42a023b9 100644
--- a/Source/WebCore/inspector/agents/InspectorPageAgent.h
+++ b/Source/WebCore/inspector/agents/InspectorPageAgent.h
@@ -40,11 +40,16 @@
 #include <wtf/Seconds.h>
 #include <wtf/text/WTFString.h>
 
+namespace Inspector {
+class InjectedScriptManager;
+}
+
 namespace WebCore {
 
 class DOMWrapperWorld;
 class DocumentLoader;
 class Frame;
+class HTMLInputElement;
 class InspectorClient;
 class InspectorOverlay;
 class Page;
@@ -97,7 +102,9 @@ public:
     void enable(ErrorString&) override;
     void disable(ErrorString&) override;
     void reload(ErrorString&, const bool* optionalReloadFromOrigin, const bool* optionalRevalidateAllResources) override;
-    void navigate(ErrorString&, const String& url) override;
+    void goBack(ErrorString&) override;
+    void goForward(ErrorString&) override;
+    void navigate(ErrorString&, const String& url, const String* frameId, const String* referrer) override;
     void overrideUserAgent(ErrorString&, const String* value) override;
     void overrideSetting(ErrorString&, const String& setting, const bool* value) override;
     void getCookies(ErrorString&, RefPtr<JSON::ArrayOf<Inspector::Protocol::Page::Cookie>>& cookies) override;
@@ -111,20 +118,30 @@ public:
     void setShowPaintRects(ErrorString&, bool show) override;
     void setEmulatedMedia(ErrorString&, const String&) override;
     void setForcedAppearance(ErrorString&, const String&) override;
+    void setTimeZone(ErrorString&, const String*) override;
+    void setTouchEmulationEnabled(ErrorString&, bool) override;
     void snapshotNode(ErrorString&, int nodeId, String* outDataURL) override;
-    void snapshotRect(ErrorString&, int x, int y, int width, int height, const String& coordinateSystem, String* outDataURL) override;
+    void snapshotRect(ErrorString&, int x, int y, int width,  int height, const String& coordinateSystem, String* outDataURL) override;
     void archive(ErrorString&, String* data) override;
+    void insertText(ErrorString&, const String& text) override;
+    void accessibilitySnapshot(ErrorString&, const String* objectId, RefPtr<Inspector::Protocol::Page::AXNode>& out_axNode) override;
+    void setInterceptFileChooserDialog(ErrorString&, bool enabled) override;
+    void setDefaultBackgroundColorOverride(ErrorString&, const JSON::Object*) override;
+    void createUserWorld(ErrorString&, const String&) override;
+    void setBypassCSP(ErrorString&, bool) override;
+    void crash(ErrorString&) override;
+    void setScreenSizeOverride(ErrorString&, int width, int height) override;
 
     // InspectorInstrumentation
-    void domContentEventFired();
-    void loadEventFired();
+    void domContentEventFired(Frame&);
+    void loadEventFired(Frame&);
     void frameNavigated(Frame&);
     void frameDetached(Frame&);
-    void loaderDetachedFromFrame(DocumentLoader&);
     void frameStartedLoading(Frame&);
     void frameStoppedLoading(Frame&);
     void frameScheduledNavigation(Frame&, Seconds delay);
     void frameClearedScheduledNavigation(Frame&);
+    void didNavigateWithinPage(Frame&);
     void defaultAppearanceDidChange(bool useDarkAppearance);
     void applyUserAgentOverride(String&);
     void applyEmulatedMedia(String&);
@@ -133,6 +150,9 @@ public:
     void didLayout();
     void didScroll();
     void didRecalculateStyle();
+    void runOpenPanel(HTMLInputElement* element, bool* intercept);
+    void frameAttached(Frame&);
+    bool shouldBypassCSP();
 
     Frame* frameForId(const String& frameId);
     WEBCORE_EXPORT String frameId(Frame*);
@@ -141,6 +161,7 @@ public:
 
 private:
     double timestamp();
+    void ensureUserWorldsExistInAllFrames(const Vector<DOMWrapperWorld*>&);
 
     static bool mainResourceContent(Frame*, bool withBase64Encode, String* result);
     static bool dataContent(const char* data, unsigned size, const String& textEncodingName, bool withBase64Encode, String* result);
@@ -152,18 +173,19 @@ private:
     RefPtr<Inspector::PageBackendDispatcher> m_backendDispatcher;
 
     Page& m_inspectedPage;
+    Inspector::InjectedScriptManager& m_injectedScriptManager;
     InspectorClient* m_client { nullptr };
     InspectorOverlay* m_overlay { nullptr };
 
-    HashMap<Frame*, String> m_frameToIdentifier;
     HashMap<String, Frame*> m_identifierToFrame;
-    HashMap<DocumentLoader*, String> m_loaderToIdentifier;
     String m_userAgentOverride;
     String m_emulatedMedia;
     String m_forcedAppearance;
     String m_bootstrapScript;
     bool m_isFirstLayoutAfterOnLoad { false };
     bool m_showPaintRects { false };
+    bool m_interceptFileChooserDialog { false };
+    bool m_bypassCSP { false };
 };
 
 } // namespace WebCore
diff --git a/Source/WebCore/inspector/agents/InspectorWorkerAgent.cpp b/Source/WebCore/inspector/agents/InspectorWorkerAgent.cpp
index 5b7d17a424be41789f73e795736defb8fdf4ed1b..ee571acbf3a4c34cd7039ddd04febe36164a7346 100644
--- a/Source/WebCore/inspector/agents/InspectorWorkerAgent.cpp
+++ b/Source/WebCore/inspector/agents/InspectorWorkerAgent.cpp
@@ -160,7 +160,11 @@ void InspectorWorkerAgent::connectToWorkerInspectorProxy(WorkerInspectorProxy* p
 
     m_connectedProxies.set(proxy->identifier(), proxy);
 
-    m_frontendDispatcher->workerCreated(proxy->identifier(), proxy->url());
+    ASSERT(is<Document>(proxy->scriptExecutionContext()));
+    Document& document = downcast<Document>(*proxy->scriptExecutionContext());
+    auto* pageAgent = m_instrumentingAgents.inspectorPageAgent();
+    m_frontendDispatcher->workerCreated(proxy->identifier(), proxy->url(),
+        pageAgent ? pageAgent->frameId(document.frame()) : emptyString());
 }
 
 void InspectorWorkerAgent::disconnectFromWorkerInspectorProxy(WorkerInspectorProxy* proxy)
diff --git a/Source/WebCore/inspector/agents/page/PageDebuggerAgent.cpp b/Source/WebCore/inspector/agents/page/PageDebuggerAgent.cpp
index cc0b0526f19f806ce621521d0771cc5f30d43840..6b54fa315ac22af78f2bf1befef204ca48308200 100644
--- a/Source/WebCore/inspector/agents/page/PageDebuggerAgent.cpp
+++ b/Source/WebCore/inspector/agents/page/PageDebuggerAgent.cpp
@@ -38,6 +38,7 @@
 #include "Frame.h"
 #include "InspectorPageAgent.h"
 #include "InstrumentingAgents.h"
+#include "JSDOMWindowBase.h"
 #include "Page.h"
 #include "PageConsoleClient.h"
 #include "PageScriptDebugServer.h"
@@ -70,8 +71,11 @@ bool PageDebuggerAgent::enabled() const
 
 void PageDebuggerAgent::evaluateOnCallFrame(ErrorString& errorString, const String& callFrameId, const String& expression, const String* objectGroup, const bool* includeCommandLineAPI, const bool* doNotPauseOnExceptionsAndMuteConsole, const bool* returnByValue, const bool* generatePreview, const bool* saveResult, const bool* emulateUserGesture, RefPtr<Protocol::Runtime::RemoteObject>& result, Optional<bool>& wasThrown, Optional<int>& savedResultIndex)
 {
+    InjectedScript injectedScript = injectedScriptManager().injectedScriptForObjectId(callFrameId);
+    JSC::JSGlobalObject* globalObject = injectedScript.globalObject();
+    Document* document = globalObject ? activeDOMWindow(*globalObject).document() : nullptr;
     auto shouldEmulateUserGesture = emulateUserGesture && *emulateUserGesture;
-    UserGestureEmulationScope userGestureScope(m_inspectedPage, shouldEmulateUserGesture);
+    UserGestureEmulationScope userGestureScope(m_inspectedPage, shouldEmulateUserGesture, document);
 
     WebDebuggerAgent::evaluateOnCallFrame(errorString, callFrameId, expression, objectGroup, includeCommandLineAPI, doNotPauseOnExceptionsAndMuteConsole, returnByValue, generatePreview, saveResult, emulateUserGesture, result, wasThrown, savedResultIndex);
 }
diff --git a/Source/WebCore/inspector/agents/page/PageRuntimeAgent.cpp b/Source/WebCore/inspector/agents/page/PageRuntimeAgent.cpp
index 63336051bb0050d6a55eb5543b0349eb964bbb7a..eecfb5a50196c6d9ca353e9b7aedbd4d6feb690c 100644
--- a/Source/WebCore/inspector/agents/page/PageRuntimeAgent.cpp
+++ b/Source/WebCore/inspector/agents/page/PageRuntimeAgent.cpp
@@ -35,12 +35,14 @@
 #include "DOMWrapperWorld.h"
 #include "Document.h"
 #include "Frame.h"
+#include "FrameLoader.h"
 #include "InspectorPageAgent.h"
 #include "InstrumentingAgents.h"
 #include "JSDOMWindowBase.h"
 #include "Page.h"
 #include "PageConsoleClient.h"
 #include "ScriptController.h"
+#include "ScriptSourceCode.h"
 #include "ScriptState.h"
 #include "SecurityOrigin.h"
 #include "UserGestureEmulationScope.h"
@@ -106,6 +108,15 @@ void PageRuntimeAgent::didClearWindowObjectInWorld(Frame& frame, DOMWrapperWorld
     notifyContextCreated(pageAgent->frameId(&frame), frame.script().globalObject(world), world);
 }
 
+void PageRuntimeAgent::didReceiveMainResourceError(Frame& frame)
+{
+    if (frame.loader().stateMachine().isDisplayingInitialEmptyDocument()) {
+        // Ensure execution context is created for the empty docment to make
+        // it usable in case loading failed.
+        mainWorldExecState(&frame);
+    }
+}
+
 InjectedScript PageRuntimeAgent::injectedScriptForEval(ErrorString& errorString, const int* executionContextId)
 {
     if (!executionContextId) {
@@ -194,13 +205,21 @@ void PageRuntimeAgent::notifyContextCreated(const String& frameId, JSC::JSGlobal
 
 void PageRuntimeAgent::evaluate(ErrorString& errorString, const String& expression, const String* objectGroup, const bool* includeCommandLineAPI, const bool* doNotPauseOnExceptionsAndMuteConsole, const int* executionContextId, const bool* returnByValue, const bool* generatePreview, const bool* saveResult, const bool* emulateUserGesture, RefPtr<Inspector::Protocol::Runtime::RemoteObject>& result, Optional<bool>& wasThrown, Optional<int>& savedResultIndex)
 {
-    UserGestureEmulationScope userGestureScope(m_inspectedPage, asBool(emulateUserGesture));
+    InjectedScript injectedScript = injectedScriptForEval(errorString, executionContextId);
+    if (!errorString.isEmpty())
+        return;
+    JSC::JSGlobalObject* globalObject = injectedScript.globalObject();
+    Document* document = globalObject ? activeDOMWindow(*globalObject).document() : nullptr;
+    UserGestureEmulationScope userGestureScope(m_inspectedPage, asBool(emulateUserGesture), document);
     InspectorRuntimeAgent::evaluate(errorString, expression, objectGroup, includeCommandLineAPI, doNotPauseOnExceptionsAndMuteConsole, executionContextId, returnByValue, generatePreview, saveResult, emulateUserGesture, result, wasThrown, savedResultIndex);
 }
 
 void PageRuntimeAgent::callFunctionOn(ErrorString& errorString, const String& objectId, const String& expression, const JSON::Array* optionalArguments, const bool* doNotPauseOnExceptionsAndMuteConsole, const bool* returnByValue, const bool* generatePreview, const bool* emulateUserGesture, RefPtr<Inspector::Protocol::Runtime::RemoteObject>& result, Optional<bool>& wasThrown)
 {
-    UserGestureEmulationScope userGestureScope(m_inspectedPage, asBool(emulateUserGesture));
+    InjectedScript injectedScript = injectedScriptManager().injectedScriptForObjectId(objectId);
+    JSC::JSGlobalObject* globalObject = injectedScript.globalObject();
+    Document* document = globalObject ? activeDOMWindow(*globalObject).document() : nullptr;
+    UserGestureEmulationScope userGestureScope(m_inspectedPage, asBool(emulateUserGesture), document);
     InspectorRuntimeAgent::callFunctionOn(errorString, objectId, expression, optionalArguments, doNotPauseOnExceptionsAndMuteConsole, returnByValue, generatePreview, emulateUserGesture, result, wasThrown);
 }
 
diff --git a/Source/WebCore/inspector/agents/page/PageRuntimeAgent.h b/Source/WebCore/inspector/agents/page/PageRuntimeAgent.h
index 2af3739b7fe7c16faa7d8d2797ce6d010215398d..80bfde6120874e16fb173f707fd0bd8a3e5067a0 100644
--- a/Source/WebCore/inspector/agents/page/PageRuntimeAgent.h
+++ b/Source/WebCore/inspector/agents/page/PageRuntimeAgent.h
@@ -63,6 +63,7 @@ public:
     // InspectorInstrumentation
     void frameNavigated(Frame&);
     void didClearWindowObjectInWorld(Frame&, DOMWrapperWorld&);
+    void didReceiveMainResourceError(Frame&);
 
 private:
     Inspector::InjectedScript injectedScriptForEval(ErrorString&, const int* executionContextId) override;
@@ -73,7 +74,6 @@ private:
 
     std::unique_ptr<Inspector::RuntimeFrontendDispatcher> m_frontendDispatcher;
     RefPtr<Inspector::RuntimeBackendDispatcher> m_backendDispatcher;
-
     InstrumentingAgents& m_instrumentingAgents;
 
     Page& m_inspectedPage;
diff --git a/Source/WebCore/inspector/agents/page/UserGestureEmulationScope.cpp b/Source/WebCore/inspector/agents/page/UserGestureEmulationScope.cpp
index 633bce6e8f3c0785632eb7f26d172f6016b3efd9..14f531504bb2b96646d1a48092a0b132b0510f55 100644
--- a/Source/WebCore/inspector/agents/page/UserGestureEmulationScope.cpp
+++ b/Source/WebCore/inspector/agents/page/UserGestureEmulationScope.cpp
@@ -39,9 +39,9 @@
 
 namespace WebCore {
 
-UserGestureEmulationScope::UserGestureEmulationScope(Page& inspectedPage, bool emulateUserGesture)
+UserGestureEmulationScope::UserGestureEmulationScope(Page& inspectedPage, bool emulateUserGesture, Document* document)
     : m_pageChromeClient(inspectedPage.chrome().client())
-    , m_gestureIndicator(emulateUserGesture ? Optional<ProcessingUserGestureState>(ProcessingUserGesture) : WTF::nullopt)
+    , m_gestureIndicator(emulateUserGesture ? Optional<ProcessingUserGestureState>(ProcessingUserGesture) : WTF::nullopt, document)
     , m_emulateUserGesture(emulateUserGesture)
     , m_userWasInteracting(false)
 {
diff --git a/Source/WebCore/inspector/agents/page/UserGestureEmulationScope.h b/Source/WebCore/inspector/agents/page/UserGestureEmulationScope.h
index b94ed78ad3dbea19543c1fd54653f0481e52fb7c..6341c7ff7ef53577f33c19ecad1b8bfbd674d051 100644
--- a/Source/WebCore/inspector/agents/page/UserGestureEmulationScope.h
+++ b/Source/WebCore/inspector/agents/page/UserGestureEmulationScope.h
@@ -38,11 +38,12 @@ namespace WebCore {
 
 class ChromeClient;
 class Page;
+class Document;
 
 class UserGestureEmulationScope {
     WTF_MAKE_NONCOPYABLE(UserGestureEmulationScope);
 public:
-    UserGestureEmulationScope(Page& inspectedPage, bool emulateUserGesture);
+    UserGestureEmulationScope(Page& inspectedPage, bool emulateUserGesture, Document* document);
     ~UserGestureEmulationScope();
 
 private:
diff --git a/Source/WebCore/loader/DocumentLoader.cpp b/Source/WebCore/loader/DocumentLoader.cpp
index da50315d2160833e02ab19b250ea19ab652246a9..f93887308eba26272449efd1c48afa68d77c4408 100644
--- a/Source/WebCore/loader/DocumentLoader.cpp
+++ b/Source/WebCore/loader/DocumentLoader.cpp
@@ -1286,8 +1286,6 @@ void DocumentLoader::detachFromFrame()
     if (!m_frame)
         return;
 
-    InspectorInstrumentation::loaderDetachedFromFrame(*m_frame, *this);
-
     observeFrame(nullptr);
 }
 
diff --git a/Source/WebCore/loader/DocumentLoader.h b/Source/WebCore/loader/DocumentLoader.h
index d6a3d0acd246de70cb485880a04b38941c832f65..61c8d5478f5eefccf88532bebf69b94d97e8a88c 100644
--- a/Source/WebCore/loader/DocumentLoader.h
+++ b/Source/WebCore/loader/DocumentLoader.h
@@ -163,9 +163,13 @@ public:
 
     WEBCORE_EXPORT virtual void detachFromFrame();
 
+    virtual void replacedByFragmentNavigation(Frame&) { }
+
     WEBCORE_EXPORT FrameLoader* frameLoader() const;
     WEBCORE_EXPORT SubresourceLoader* mainResourceLoader() const;
     WEBCORE_EXPORT RefPtr<SharedBuffer> mainResourceData() const;
+
+    virtual uint64_t loaderIDForInspector() { return 0; }
     
     DocumentWriter& writer() const { return m_writer; }
 
diff --git a/Source/WebCore/loader/FrameLoader.cpp b/Source/WebCore/loader/FrameLoader.cpp
index 8cf9c5c47cea3ad27f282b5d73cfd5d6e3e7834a..3c5b8808424f849925f5fcb3ac97d10eee2f5f07 100644
--- a/Source/WebCore/loader/FrameLoader.cpp
+++ b/Source/WebCore/loader/FrameLoader.cpp
@@ -1178,6 +1178,7 @@ void FrameLoader::loadInSameDocument(const URL& url, SerializedScriptValue* stat
     }
 
     m_client.dispatchDidNavigateWithinPage();
+    InspectorInstrumentation::didNavigateWithinPage(m_frame);
 
     m_frame.document()->statePopped(stateObject ? Ref<SerializedScriptValue> { *stateObject } : SerializedScriptValue::nullValue());
     m_client.dispatchDidPopStateWithinPage();
@@ -1363,6 +1364,8 @@ void FrameLoader::loadURL(FrameLoadRequest&& frameLoadRequest, const String& ref
 
     ASSERT(newLoadType != FrameLoadType::Same);
 
+    request.setInitiatorIdentifier(frameLoadRequest.resourceRequest().initiatorIdentifier());
+
     // The search for a target frame is done earlier in the case of form submission.
     Frame* targetFrame = isFormSubmission ? nullptr : findFrameForNavigation(effectiveFrameName);
     if (targetFrame && targetFrame != &m_frame) {
@@ -1495,6 +1498,7 @@ void FrameLoader::load(FrameLoadRequest&& request)
 
 void FrameLoader::loadWithNavigationAction(const ResourceRequest& request, NavigationAction&& action, LockHistory lockHistory, FrameLoadType type, RefPtr<FormState>&& formState, AllowNavigationToInvalidURL allowNavigationToInvalidURL, const String& downloadAttribute, CompletionHandler<void()>&& completionHandler)
 {
+    InspectorInstrumentation::frameScheduledNavigation(m_frame, Seconds(0));
     FRAMELOADER_RELEASE_LOG_IF_ALLOWED(ResourceLoading, "loadWithNavigationAction: frame load started");
 
     Ref<DocumentLoader> loader = m_client.createDocumentLoader(request, defaultSubstituteDataForURL(request.url()));
@@ -1597,6 +1601,8 @@ void FrameLoader::loadWithDocumentLoader(DocumentLoader* loader, FrameLoadType t
     const String& httpMethod = loader->request().httpMethod();
 
     if (shouldPerformFragmentNavigation(isFormSubmission, httpMethod, policyChecker().loadType(), newURL)) {
+        loader->replacedByFragmentNavigation(m_frame);
+
         RefPtr<DocumentLoader> oldDocumentLoader = m_documentLoader;
         NavigationAction action { *m_frame.document(), loader->request(), InitiatedByMainFrame::Unknown, policyChecker().loadType(), isFormSubmission };
 
@@ -3182,6 +3188,8 @@ void FrameLoader::receivedMainResourceError(const ResourceError& error)
     checkCompleted();
     if (m_frame.page())
         checkLoadComplete();
+
+    InspectorInstrumentation::didReceiveMainResourceError(m_frame, error);
 }
 
 void FrameLoader::continueFragmentScrollAfterNavigationPolicy(const ResourceRequest& request, bool shouldContinue)
@@ -3944,9 +3952,6 @@ String FrameLoader::referrer() const
 
 void FrameLoader::dispatchDidClearWindowObjectsInAllWorlds()
 {
-    if (!m_frame.script().canExecuteScripts(NotAboutToExecuteScript))
-        return;
-
     Vector<Ref<DOMWrapperWorld>> worlds;
     ScriptController::getAllWorlds(worlds);
     for (auto& world : worlds)
@@ -3955,13 +3960,13 @@ void FrameLoader::dispatchDidClearWindowObjectsInAllWorlds()
 
 void FrameLoader::dispatchDidClearWindowObjectInWorld(DOMWrapperWorld& world)
 {
-    if (!m_frame.script().canExecuteScripts(NotAboutToExecuteScript) || !m_frame.windowProxy().existingJSWindowProxy(world))
-        return;
+    if (m_frame.windowProxy().existingJSWindowProxy(world)) {
+        if (m_frame.script().canExecuteScripts(NotAboutToExecuteScript))
+            m_client.dispatchDidClearWindowObjectInWorld(world);
 
-    m_client.dispatchDidClearWindowObjectInWorld(world);
-
-    if (Page* page = m_frame.page())
-        page->inspectorController().didClearWindowObjectInWorld(m_frame, world);
+        if (Page* page = m_frame.page())
+            page->inspectorController().didClearWindowObjectInWorld(m_frame, world);
+    }
 
     InspectorInstrumentation::didClearWindowObjectInWorld(m_frame, world);
 }
diff --git a/Source/WebCore/loader/LoaderStrategy.h b/Source/WebCore/loader/LoaderStrategy.h
index 0644fec509e60f7a4cf59a352f32335c2d164d99..acf628996ea020a8f0a2239ef72f5c241d108840 100644
--- a/Source/WebCore/loader/LoaderStrategy.h
+++ b/Source/WebCore/loader/LoaderStrategy.h
@@ -79,6 +79,7 @@ public:
 
     virtual bool isOnLine() const = 0;
     virtual void addOnlineStateChangeListener(WTF::Function<void(bool)>&&) = 0;
+    virtual void setEmulateOfflineState(bool) {};
 
     virtual bool shouldPerformSecurityChecks() const { return false; }
     virtual bool havePerformedSecurityChecks(const ResourceResponse&) const { return false; }
diff --git a/Source/WebCore/loader/ProgressTracker.cpp b/Source/WebCore/loader/ProgressTracker.cpp
index e24fded2225f1c1918f454017566717e20484eab..30e4b7a986418c4b4f6c799b858b608206e22bb5 100644
--- a/Source/WebCore/loader/ProgressTracker.cpp
+++ b/Source/WebCore/loader/ProgressTracker.cpp
@@ -154,6 +154,8 @@ void ProgressTracker::progressCompleted(Frame& frame)
     if (!m_numProgressTrackedFrames || m_originatingProgressFrame == &frame)
         finalProgressComplete();
 
+    InspectorInstrumentation::frameStoppedLoading(frame);
+
     m_client->didChangeEstimatedProgress();
 }
 
@@ -179,8 +181,6 @@ void ProgressTracker::finalProgressComplete()
     frame->loader().client().setMainFrameDocumentReady(true);
     m_client->progressFinished(*frame);
     frame->loader().loadProgressingStatusChanged();
-
-    InspectorInstrumentation::frameStoppedLoading(*frame);
 }
 
 void ProgressTracker::incrementProgress(unsigned long identifier, const ResourceResponse& response)
diff --git a/Source/WebCore/page/EventHandler.cpp b/Source/WebCore/page/EventHandler.cpp
index fab4acf350950555c0ab6afc8f4ae97edae37c21..eed8f8fd6e1c827667bf1e49da26fc111cf5c859 100644
--- a/Source/WebCore/page/EventHandler.cpp
+++ b/Source/WebCore/page/EventHandler.cpp
@@ -808,9 +808,7 @@ bool EventHandler::handleMousePressEvent(const MouseEventWithHitTestResults& eve
     m_mousePressNode = event.targetNode();
     m_frame.document()->setFocusNavigationStartingNode(event.targetNode());
 
-#if ENABLE(DRAG_SUPPORT)
     m_dragStartPosition = event.event().position();
-#endif
 
     m_mousePressed = true;
     m_selectionInitiationState = HaveNotStartedSelection;
@@ -849,8 +847,6 @@ VisiblePosition EventHandler::selectionExtentRespectingEditingBoundary(const Vis
     return targetNode->renderer()->positionForPoint(LayoutPoint(selectionEndPoint), nullptr);
 }
 
-#if ENABLE(DRAG_SUPPORT)
-
 #if !PLATFORM(IOS_FAMILY)
 
 bool EventHandler::supportsSelectionUpdatesOnMouseDrag() const
@@ -872,8 +868,10 @@ bool EventHandler::handleMouseDraggedEvent(const MouseEventWithHitTestResults& e
 
     Ref<Frame> protectedFrame(m_frame);
 
+#if ENABLE(DRAG_SUPPORT)
     if (handleDrag(event, checkDragHysteresis))
         return true;
+#endif
 
     Node* targetNode = event.targetNode();
     if (event.event().button() != LeftButton || !targetNode)
@@ -894,7 +892,9 @@ bool EventHandler::handleMouseDraggedEvent(const MouseEventWithHitTestResults& e
     ASSERT(m_mouseDownMayStartSelect || m_mouseDownMayStartAutoscroll);
 #endif
 
+#if ENABLE(DRAG_SUPPORT)
     m_mouseDownMayStartDrag = false;
+#endif
 
     if (m_mouseDownMayStartAutoscroll && !panScrollInProgress()) {
         m_autoscrollController->startAutoscrollForSelection(renderer);
@@ -911,6 +911,8 @@ bool EventHandler::handleMouseDraggedEvent(const MouseEventWithHitTestResults& e
     return true;
 }
     
+#if ENABLE(DRAG_SUPPORT)
+
 bool EventHandler::eventMayStartDrag(const PlatformMouseEvent& event) const
 {
     // This is a pre-flight check of whether the event might lead to a drag being started.  Be careful
@@ -942,6 +944,8 @@ bool EventHandler::eventMayStartDrag(const PlatformMouseEvent& event) const
     return targetElement && page->dragController().draggableElement(&m_frame, targetElement, result.roundedPointInInnerNodeFrame(), state);
 }
 
+#endif // ENABLE(DRAG_SUPPORT)
+
 void EventHandler::updateSelectionForMouseDrag()
 {
     if (!supportsSelectionUpdatesOnMouseDrag())
@@ -1033,7 +1037,6 @@ void EventHandler::updateSelectionForMouseDrag(const HitTestResult& hitTestResul
     m_frame.selection().setSelectionByMouseIfDifferent(newSelection, m_frame.selection().granularity(),
         FrameSelection::AdjustEndpointsAtBidiBoundary);
 }
-#endif // ENABLE(DRAG_SUPPORT)
 
 void EventHandler::lostMouseCapture()
 {
@@ -1081,9 +1084,7 @@ bool EventHandler::handleMouseReleaseEvent(const MouseEventWithHitTestResults& e
     // on the selection, the selection goes away.  However, if we are
     // editing, place the caret.
     if (m_mouseDownWasSingleClickInSelection && m_selectionInitiationState != ExtendedSelection
-#if ENABLE(DRAG_SUPPORT)
             && m_dragStartPosition == event.event().position()
-#endif
             && m_frame.selection().isRange()
             && event.event().button() != RightButton) {
         VisibleSelection newSelection;
@@ -2036,10 +2037,8 @@ bool EventHandler::handleMouseMoveEvent(const PlatformMouseEvent& platformMouseE
         return true;
     
     swallowEvent = !dispatchMouseEvent(eventNames().mousemoveEvent, mouseEvent.targetNode(), false, 0, platformMouseEvent, true);
-#if ENABLE(DRAG_SUPPORT)
     if (!swallowEvent)
         swallowEvent = handleMouseDraggedEvent(mouseEvent);
-#endif
 
     return swallowEvent;
 }
diff --git a/Source/WebCore/page/EventHandler.h b/Source/WebCore/page/EventHandler.h
index b7c81202607dc861e540edb1ce905c048eccf4c0..5be47c8d7aebe4e3505359df057949d46d52b55e 100644
--- a/Source/WebCore/page/EventHandler.h
+++ b/Source/WebCore/page/EventHandler.h
@@ -132,9 +132,7 @@ public:
 
     WEBCORE_EXPORT VisiblePosition selectionExtentRespectingEditingBoundary(const VisibleSelection&, const LayoutPoint&, Node*);
 
-#if ENABLE(DRAG_SUPPORT)
     void updateSelectionForMouseDrag();
-#endif
 
 #if ENABLE(PAN_SCROLLING)
     void didPanScrollStart();
@@ -366,10 +364,8 @@ private:
     bool handleMousePressEventDoubleClick(const MouseEventWithHitTestResults&);
     bool handleMousePressEventTripleClick(const MouseEventWithHitTestResults&);
 
-#if ENABLE(DRAG_SUPPORT)
     bool handleMouseDraggedEvent(const MouseEventWithHitTestResults&, CheckDragHysteresis = ShouldCheckDragHysteresis);
     bool shouldAllowMouseDownToStartDrag() const;
-#endif
 
     WEBCORE_EXPORT bool handleMouseReleaseEvent(const MouseEventWithHitTestResults&);
 
@@ -456,10 +452,8 @@ private:
     void defaultTabEventHandler(KeyboardEvent&);
     void defaultArrowEventHandler(FocusDirection, KeyboardEvent&);
 
-#if ENABLE(DRAG_SUPPORT)
     DragSourceAction updateDragSourceActionsAllowed() const;
     bool supportsSelectionUpdatesOnMouseDrag() const;
-#endif
 
     // The following are called at the beginning of handleMouseUp and handleDrag.  
     // If they return true it indicates that they have consumed the event.
@@ -467,9 +461,10 @@ private:
 
 #if ENABLE(DRAG_SUPPORT)
     bool eventLoopHandleMouseDragged(const MouseEventWithHitTestResults&);
-    void updateSelectionForMouseDrag(const HitTestResult&);
 #endif
 
+    void updateSelectionForMouseDrag(const HitTestResult&);
+
     enum class SetOrClearLastScrollbar { Clear, Set };
     void updateLastScrollbarUnderMouse(Scrollbar*, SetOrClearLastScrollbar);
     
@@ -519,10 +514,7 @@ private:
     enum SelectionInitiationState { HaveNotStartedSelection, PlacedCaret, ExtendedSelection };
     SelectionInitiationState m_selectionInitiationState { HaveNotStartedSelection };
 
-#if ENABLE(DRAG_SUPPORT)
     LayoutPoint m_dragStartPosition;
-#endif
-
     Timer m_hoverTimer;
     Timer m_cursorUpdateTimer;
 
diff --git a/Source/WebCore/page/Frame.cpp b/Source/WebCore/page/Frame.cpp
index 167f7eb3038e3ddbde757c0adf569073650ed859..a9a4aec0fdc1b4c483967fb332668be3b39dc7cc 100644
--- a/Source/WebCore/page/Frame.cpp
+++ b/Source/WebCore/page/Frame.cpp
@@ -180,6 +180,7 @@ Frame::Frame(Page& page, HTMLFrameOwnerElement* ownerElement, FrameLoaderClient&
 void Frame::init()
 {
     m_loader->init();
+    InspectorInstrumentation::frameAttached(this);
 }
 
 Ref<Frame> Frame::create(Page* page, HTMLFrameOwnerElement* ownerElement, FrameLoaderClient* client)
diff --git a/Source/WebCore/page/FrameView.cpp b/Source/WebCore/page/FrameView.cpp
index 95f5b95b1f472169a87ed09c2af8cf8cacb8b9e2..ca1b0d768a686bd1bdd13f0420a73120b8cf69ae 100644
--- a/Source/WebCore/page/FrameView.cpp
+++ b/Source/WebCore/page/FrameView.cpp
@@ -3039,7 +3039,7 @@ void FrameView::setBaseBackgroundColor(const Color& backgroundColor)
 
 void FrameView::updateBackgroundRecursively(const Optional<Color>& backgroundColor)
 {
-#if HAVE(OS_DARK_MODE_SUPPORT)
+#if HAVE(OS_DARK_MODE_SUPPORT) && (defined(WTF_PLATFORM_MAC) && WTF_PLATFORM_MAC) || (defined(WTF_PLATFORM_IOS_FAMILY) && WTF_PLATFORM_IOS_FAMILY)
     Color baseBackgroundColor = backgroundColor.valueOr(RenderTheme::singleton().systemColor(CSSValueAppleSystemControlBackground, styleColorOptions()));
 #else
     Color baseBackgroundColor = backgroundColor.valueOr(Color::white);
diff --git a/Source/WebCore/page/History.cpp b/Source/WebCore/page/History.cpp
index 9c58b06f4c471130ce4815f11d14cb78f81b49a0..3d624733c36f09518b12095d91e67a2ae67879e2 100644
--- a/Source/WebCore/page/History.cpp
+++ b/Source/WebCore/page/History.cpp
@@ -259,6 +259,7 @@ ExceptionOr<void> History::stateObjectAdded(RefPtr<SerializedScriptValue>&& data
 
     if (!urlString.isEmpty())
         frame->document()->updateURLForPushOrReplaceState(fullURL);
+    InspectorInstrumentation::didNavigateWithinPage(*frame);
 
     if (stateObjectType == StateObjectType::Push) {
         frame->loader().history().pushState(WTFMove(data), title, fullURL.string());
diff --git a/Source/WebCore/page/Page.cpp b/Source/WebCore/page/Page.cpp
index 7c20fec304a4c90e57a3835dd329134b6ec256dc..cf60f6e042659af1d71317f8a8b018486da21db7 100644
--- a/Source/WebCore/page/Page.cpp
+++ b/Source/WebCore/page/Page.cpp
@@ -86,6 +86,7 @@
 #include "PerformanceLoggingClient.h"
 #include "PerformanceMonitor.h"
 #include "PlatformMediaSessionManager.h"
+#include "PlatformScreen.h"
 #include "PlatformStrategies.h"
 #include "PlugInClient.h"
 #include "PluginData.h"
@@ -421,6 +422,21 @@ void Page::setOverrideViewportArguments(const Optional<ViewportArguments>& viewp
         document->updateViewportArguments();
 }
 
+FloatSize Page::screenSize()
+{
+    return m_overrideScreenSize.valueOr(screenRect(mainFrame().view()).size());
+}
+
+void Page::setOverrideScreenSize(Optional<FloatSize> size)
+{
+    if (size == m_overrideScreenSize)
+        return;
+
+    m_overrideScreenSize = size;
+    if (auto* document = mainFrame().document())
+        document->updateViewportArguments();
+}
+
 ScrollingCoordinator* Page::scrollingCoordinator()
 {
     if (!m_scrollingCoordinator && m_settings->scrollingCoordinatorEnabled()) {
diff --git a/Source/WebCore/page/Page.h b/Source/WebCore/page/Page.h
index 37ca2497bb3a6ca8baf1a5fb45eabcf682b9896b..6bc1c51e7a5f02d7e7ad7c1c898066374678f16f 100644
--- a/Source/WebCore/page/Page.h
+++ b/Source/WebCore/page/Page.h
@@ -185,6 +185,9 @@ public:
     const Optional<ViewportArguments>& overrideViewportArguments() const { return m_overrideViewportArguments; }
     WEBCORE_EXPORT void setOverrideViewportArguments(const Optional<ViewportArguments>&);
 
+    WEBCORE_EXPORT FloatSize screenSize();
+    WEBCORE_EXPORT void setOverrideScreenSize(Optional<FloatSize> size);
+
     static void refreshPlugins(bool reload);
     WEBCORE_EXPORT PluginData& pluginData();
     void clearPluginData();
@@ -993,6 +996,7 @@ private:
 #endif
 
     Optional<ViewportArguments> m_overrideViewportArguments;
+    Optional<FloatSize> m_overrideScreenSize;
 
 #if ENABLE(DEVICE_ORIENTATION) && PLATFORM(IOS_FAMILY)
     RefPtr<DeviceOrientationUpdateProvider> m_deviceOrientationUpdateProvider;
diff --git a/Source/WebCore/page/Screen.cpp b/Source/WebCore/page/Screen.cpp
index a9d228ca404918860c40651994db78a1e76db5ca..1fc3c345308dfed8384d1c02334f2030e879383d 100644
--- a/Source/WebCore/page/Screen.cpp
+++ b/Source/WebCore/page/Screen.cpp
@@ -32,6 +32,7 @@
 #include "FloatRect.h"
 #include "Frame.h"
 #include "FrameView.h"
+#include "Page.h"
 #include "PlatformScreen.h"
 #include "ResourceLoadObserver.h"
 #include "RuntimeEnabledFeatures.h"
@@ -53,7 +54,7 @@ unsigned Screen::height() const
         return 0;
     if (RuntimeEnabledFeatures::sharedFeatures().webAPIStatisticsEnabled())
         ResourceLoadObserver::shared().logScreenAPIAccessed(*frame->document(), ResourceLoadStatistics::ScreenAPI::Height);
-    long height = static_cast<long>(screenRect(frame->view()).height());
+    long height = static_cast<long>(frame->page()->screenSize().height());
     return static_cast<unsigned>(height);
 }
 
@@ -64,7 +65,7 @@ unsigned Screen::width() const
         return 0;
     if (RuntimeEnabledFeatures::sharedFeatures().webAPIStatisticsEnabled())
         ResourceLoadObserver::shared().logScreenAPIAccessed(*frame->document(), ResourceLoadStatistics::ScreenAPI::Width);
-    long width = static_cast<long>(screenRect(frame->view()).width());
+    long width = static_cast<long>(frame->page()->screenSize().width());
     return static_cast<unsigned>(width);
 }
 
diff --git a/Source/WebCore/page/csp/ContentSecurityPolicy.cpp b/Source/WebCore/page/csp/ContentSecurityPolicy.cpp
index ad6f5209c52e0842d93be267f8f5e99551dfe07c..0fcf4fe9877ba8a89a8dfb321e120f7954c6f69b 100644
--- a/Source/WebCore/page/csp/ContentSecurityPolicy.cpp
+++ b/Source/WebCore/page/csp/ContentSecurityPolicy.cpp
@@ -298,6 +298,8 @@ bool ContentSecurityPolicy::protocolMatchesSelf(const URL& url) const
 template<typename Predicate, typename... Args>
 typename std::enable_if<!std::is_convertible<Predicate, ContentSecurityPolicy::ViolatedDirectiveCallback>::value, bool>::type ContentSecurityPolicy::allPoliciesWithDispositionAllow(Disposition disposition, Predicate&& predicate, Args&&... args) const
 {
+    if (InspectorInstrumentation::shouldBypassCSP(m_scriptExecutionContext))
+        return true;
     bool isReportOnly = disposition == ContentSecurityPolicy::Disposition::ReportOnly;
     for (auto& policy : m_policies) {
         if (policy->isReportOnly() != isReportOnly)
@@ -311,6 +313,8 @@ typename std::enable_if<!std::is_convertible<Predicate, ContentSecurityPolicy::V
 template<typename Predicate, typename... Args>
 bool ContentSecurityPolicy::allPoliciesWithDispositionAllow(Disposition disposition, ViolatedDirectiveCallback&& callback, Predicate&& predicate, Args&&... args) const
 {
+    if (InspectorInstrumentation::shouldBypassCSP(m_scriptExecutionContext))
+        return true;
     bool isReportOnly = disposition == ContentSecurityPolicy::Disposition::ReportOnly;
     bool isAllowed = true;
     for (auto& policy : m_policies) {
@@ -327,6 +331,8 @@ bool ContentSecurityPolicy::allPoliciesWithDispositionAllow(Disposition disposit
 template<typename Predicate, typename... Args>
 bool ContentSecurityPolicy::allPoliciesAllow(ViolatedDirectiveCallback&& callback, Predicate&& predicate, Args&&... args) const
 {
+    if (InspectorInstrumentation::shouldBypassCSP(m_scriptExecutionContext))
+        return true;
     bool isAllowed = true;
     for (auto& policy : m_policies) {
         if (const ContentSecurityPolicyDirective* violatedDirective = (policy.get()->*predicate)(std::forward<Args>(args)...)) {
diff --git a/Source/WebCore/platform/PlatformKeyboardEvent.h b/Source/WebCore/platform/PlatformKeyboardEvent.h
index f423a4a1d5399326fc48fe4d4a8a8fb9d4df861e..b4b60162d8b0d34113df052b04a1695d481d266e 100644
--- a/Source/WebCore/platform/PlatformKeyboardEvent.h
+++ b/Source/WebCore/platform/PlatformKeyboardEvent.h
@@ -138,6 +138,7 @@ namespace WebCore {
         static String keyCodeForHardwareKeyCode(unsigned);
         static String keyIdentifierForGdkKeyCode(unsigned);
         static int windowsKeyCodeForGdkKeyCode(unsigned);
+        static unsigned gdkKeyCodeForWindowsKeyCode(int);
         static String singleCharacterString(unsigned);
         static bool modifiersContainCapsLock(unsigned);
 #endif
@@ -147,6 +148,7 @@ namespace WebCore {
         static String keyCodeForHardwareKeyCode(unsigned);
         static String keyIdentifierForWPEKeyCode(unsigned);
         static int windowsKeyCodeForWPEKeyCode(unsigned);
+        static unsigned WPEKeyCodeForWindowsKeyCode(int);
         static String singleCharacterString(unsigned);
 #endif
 
diff --git a/Source/WebCore/platform/ScrollableArea.h b/Source/WebCore/platform/ScrollableArea.h
index fdddf2f9beb7e0b28f072cb121d1ee117bf00969..6c6acba2e5795319b60bd3031f37d8872d5a2011 100644
--- a/Source/WebCore/platform/ScrollableArea.h
+++ b/Source/WebCore/platform/ScrollableArea.h
@@ -103,7 +103,7 @@ public:
     void updateScrollSnapState();
 
 #if ENABLE(TOUCH_EVENTS)
-    virtual bool handleTouchEvent(const PlatformTouchEvent&);
+    WEBCORE_EXPORT virtual bool handleTouchEvent(const PlatformTouchEvent&);
 #endif
 
 #if PLATFORM(IOS_FAMILY)
diff --git a/Source/WebCore/platform/graphics/opengl/GraphicsContextGLOpenGLBase.cpp b/Source/WebCore/platform/graphics/opengl/GraphicsContextGLOpenGLBase.cpp
index 3cc3dc9012e8ff409141dd43808b71264c8cd337..e44eca80b5a7f0ac8360d39d78ec7097d5296dc3 100644
--- a/Source/WebCore/platform/graphics/opengl/GraphicsContextGLOpenGLBase.cpp
+++ b/Source/WebCore/platform/graphics/opengl/GraphicsContextGLOpenGLBase.cpp
@@ -27,7 +27,7 @@
 #include "config.h"
 #include "GraphicsContextGLOpenGL.h"
 
-#if ENABLE(GRAPHICS_CONTEXT_GL) && (USE(OPENGL) || (PLATFORM(COCOA) && USE(OPENGL_ES)))
+#if !PLATFORM(WIN) && ENABLE(GRAPHICS_CONTEXT_GL) && (USE(OPENGL) || (PLATFORM(COCOA) && USE(OPENGL_ES)))
 
 #if PLATFORM(IOS_FAMILY)
 #include "GraphicsContextGLOpenGLESIOS.h"
diff --git a/Source/WebCore/platform/gtk/PlatformKeyboardEventGtk.cpp b/Source/WebCore/platform/gtk/PlatformKeyboardEventGtk.cpp
index 269008b9053c8d8b6787cf22f13b44b46dace333..d3ba16947bc8964a7cfe746cabbf99d32a673cef 100644
--- a/Source/WebCore/platform/gtk/PlatformKeyboardEventGtk.cpp
+++ b/Source/WebCore/platform/gtk/PlatformKeyboardEventGtk.cpp
@@ -36,8 +36,10 @@
 #include "WindowsKeyboardCodes.h"
 #include <gdk/gdk.h>
 #include <gdk/gdkkeysyms.h>
+#include <wtf/HashMap.h>
 #include <wtf/HexNumber.h>
 #include <wtf/glib/GUniquePtr.h>
+#include <mutex>
 
 namespace WebCore {
 
@@ -1293,6 +1295,246 @@ int PlatformKeyboardEvent::windowsKeyCodeForGdkKeyCode(unsigned keycode)
 
 }
 
+static const HashMap<int, unsigned>& gdkToWindowsKeyCodeMap()
+{
+    static HashMap<int, unsigned>* result;
+    static std::once_flag once;
+    std::call_once(
+        once,
+        [] {
+            const unsigned gdkKeyCodes[] = {
+                GDK_KEY_Cancel,
+                // FIXME: non-keypad keys should take precedence, so we skip GDK_KEY_KP_*
+                // GDK_KEY_KP_0,
+                // GDK_KEY_KP_1,
+                // GDK_KEY_KP_2,
+                // GDK_KEY_KP_3,
+                // GDK_KEY_KP_4,
+                // GDK_KEY_KP_5,
+                // GDK_KEY_KP_6,
+                // GDK_KEY_KP_7,
+                // GDK_KEY_KP_8,
+                // GDK_KEY_KP_9,
+                // GDK_KEY_KP_Multiply,
+                // GDK_KEY_KP_Add,
+                // GDK_KEY_KP_Subtract,
+                // GDK_KEY_KP_Decimal,
+                // GDK_KEY_KP_Divide,
+                // GDK_KEY_KP_Page_Up,
+                // GDK_KEY_KP_Page_Down,
+                // GDK_KEY_KP_End,
+                // GDK_KEY_KP_Home,
+                // GDK_KEY_KP_Left,
+                // GDK_KEY_KP_Up,
+                // GDK_KEY_KP_Right,
+                // GDK_KEY_KP_Down,
+                GDK_KEY_BackSpace,
+                // GDK_KEY_ISO_Left_Tab,
+                // GDK_KEY_3270_BackTab,
+                GDK_KEY_Tab,
+                GDK_KEY_Clear,
+                // GDK_KEY_ISO_Enter,
+                // GDK_KEY_KP_Enter,
+                GDK_KEY_Return,
+                GDK_KEY_Menu,
+                GDK_KEY_Pause,
+                GDK_KEY_AudioPause,
+                GDK_KEY_Caps_Lock,
+                GDK_KEY_Kana_Lock,
+                GDK_KEY_Kana_Shift,
+                GDK_KEY_Hangul,
+                GDK_KEY_Hangul_Hanja,
+                GDK_KEY_Kanji,
+                GDK_KEY_Escape,
+                GDK_KEY_space,
+                GDK_KEY_Page_Up,
+                GDK_KEY_Page_Down,
+                GDK_KEY_End,
+                GDK_KEY_Home,
+                GDK_KEY_Left,
+                GDK_KEY_Up,
+                GDK_KEY_Right,
+                GDK_KEY_Down,
+                GDK_KEY_Select,
+                GDK_KEY_Print,
+                GDK_KEY_Execute,
+                GDK_KEY_Insert,
+                GDK_KEY_KP_Insert,
+                GDK_KEY_Delete,
+                GDK_KEY_KP_Delete,
+                GDK_KEY_Help,
+                GDK_KEY_0,
+                GDK_KEY_parenright,
+                GDK_KEY_1,
+                GDK_KEY_exclam,
+                GDK_KEY_2,
+                GDK_KEY_at,
+                GDK_KEY_3,
+                GDK_KEY_numbersign,
+                GDK_KEY_4,
+                GDK_KEY_dollar,
+                GDK_KEY_5,
+                GDK_KEY_percent,
+                GDK_KEY_6,
+                GDK_KEY_asciicircum,
+                GDK_KEY_7,
+                GDK_KEY_ampersand,
+                GDK_KEY_8,
+                GDK_KEY_asterisk,
+                GDK_KEY_9,
+                GDK_KEY_parenleft,
+                GDK_KEY_a,
+                GDK_KEY_A,
+                GDK_KEY_b,
+                GDK_KEY_B,
+                GDK_KEY_c,
+                GDK_KEY_C,
+                GDK_KEY_d,
+                GDK_KEY_D,
+                GDK_KEY_e,
+                GDK_KEY_E,
+                GDK_KEY_f,
+                GDK_KEY_F,
+                GDK_KEY_g,
+                GDK_KEY_G,
+                GDK_KEY_h,
+                GDK_KEY_H,
+                GDK_KEY_i,
+                GDK_KEY_I,
+                GDK_KEY_j,
+                GDK_KEY_J,
+                GDK_KEY_k,
+                GDK_KEY_K,
+                GDK_KEY_l,
+                GDK_KEY_L,
+                GDK_KEY_m,
+                GDK_KEY_M,
+                GDK_KEY_n,
+                GDK_KEY_N,
+                GDK_KEY_o,
+                GDK_KEY_O,
+                GDK_KEY_p,
+                GDK_KEY_P,
+                GDK_KEY_q,
+                GDK_KEY_Q,
+                GDK_KEY_r,
+                GDK_KEY_R,
+                GDK_KEY_s,
+                GDK_KEY_S,
+                GDK_KEY_t,
+                GDK_KEY_T,
+                GDK_KEY_u,
+                GDK_KEY_U,
+                GDK_KEY_v,
+                GDK_KEY_V,
+                GDK_KEY_w,
+                GDK_KEY_W,
+                GDK_KEY_x,
+                GDK_KEY_X,
+                GDK_KEY_y,
+                GDK_KEY_Y,
+                GDK_KEY_z,
+                GDK_KEY_Z,
+                GDK_KEY_Meta_L,
+                GDK_KEY_Meta_R,
+                GDK_KEY_Sleep,
+                GDK_KEY_Num_Lock,
+                GDK_KEY_Scroll_Lock,
+                GDK_KEY_Shift_L,
+                GDK_KEY_Shift_R,
+                GDK_KEY_Control_L,
+                GDK_KEY_Control_R,
+                GDK_KEY_Alt_L,
+                GDK_KEY_Alt_R,
+                GDK_KEY_Back,
+                GDK_KEY_Forward,
+                GDK_KEY_Refresh,
+                GDK_KEY_Stop,
+                GDK_KEY_Search,
+                GDK_KEY_Favorites,
+                GDK_KEY_HomePage,
+                GDK_KEY_AudioMute,
+                GDK_KEY_AudioLowerVolume,
+                GDK_KEY_AudioRaiseVolume,
+                GDK_KEY_AudioNext,
+                GDK_KEY_AudioPrev,
+                GDK_KEY_AudioStop,
+                GDK_KEY_AudioMedia,
+                GDK_KEY_semicolon,
+                GDK_KEY_colon,
+                GDK_KEY_plus,
+                GDK_KEY_equal,
+                GDK_KEY_comma,
+                GDK_KEY_less,
+                GDK_KEY_minus,
+                GDK_KEY_underscore,
+                GDK_KEY_period,
+                GDK_KEY_greater,
+                GDK_KEY_slash,
+                GDK_KEY_question,
+                GDK_KEY_asciitilde,
+                GDK_KEY_quoteleft,
+                GDK_KEY_bracketleft,
+                GDK_KEY_braceleft,
+                GDK_KEY_backslash,
+                GDK_KEY_bar,
+                GDK_KEY_bracketright,
+                GDK_KEY_braceright,
+                GDK_KEY_quoteright,
+                GDK_KEY_quotedbl,
+                GDK_KEY_AudioRewind,
+                GDK_KEY_AudioForward,
+                GDK_KEY_AudioPlay,
+                GDK_KEY_F1,
+                GDK_KEY_F2,
+                GDK_KEY_F3,
+                GDK_KEY_F4,
+                GDK_KEY_F5,
+                GDK_KEY_F6,
+                GDK_KEY_F7,
+                GDK_KEY_F8,
+                GDK_KEY_F9,
+                GDK_KEY_F10,
+                GDK_KEY_F11,
+                GDK_KEY_F12,
+                GDK_KEY_F13,
+                GDK_KEY_F14,
+                GDK_KEY_F15,
+                GDK_KEY_F16,
+                GDK_KEY_F17,
+                GDK_KEY_F18,
+                GDK_KEY_F19,
+                GDK_KEY_F20,
+                GDK_KEY_F21,
+                GDK_KEY_F22,
+                GDK_KEY_F23,
+                GDK_KEY_F24,
+                GDK_KEY_VoidSymbol,
+                GDK_KEY_Red,
+                GDK_KEY_Green,
+                GDK_KEY_Yellow,
+                GDK_KEY_Blue,
+                GDK_KEY_PowerOff,
+                GDK_KEY_AudioRecord,
+                GDK_KEY_Display,
+                GDK_KEY_Subtitle,
+                GDK_KEY_Video
+            };
+            result = new HashMap<int, unsigned>();
+            for (unsigned gdkKeyCode : gdkKeyCodes) {
+                int winKeyCode = PlatformKeyboardEvent::windowsKeyCodeForGdkKeyCode(gdkKeyCode);
+                // If several gdk key codes map to the same win key code first one is used.
+                result->add(winKeyCode, gdkKeyCode);
+            }
+        });
+    return *result;
+}
+
+unsigned PlatformKeyboardEvent::gdkKeyCodeForWindowsKeyCode(int keycode)
+{
+    return gdkToWindowsKeyCodeMap().get(keycode);
+}
+
 String PlatformKeyboardEvent::singleCharacterString(unsigned val)
 {
     switch (val) {
diff --git a/Source/WebCore/platform/libwpe/PlatformKeyboardEventLibWPE.cpp b/Source/WebCore/platform/libwpe/PlatformKeyboardEventLibWPE.cpp
index a34dc220bbb9a92b40dfb463e8724e81ac745b2c..8ecedd5dae88469366a619b96960598c1232a32d 100644
--- a/Source/WebCore/platform/libwpe/PlatformKeyboardEventLibWPE.cpp
+++ b/Source/WebCore/platform/libwpe/PlatformKeyboardEventLibWPE.cpp
@@ -30,8 +30,10 @@
 
 #include "WindowsKeyboardCodes.h"
 #include <wpe/wpe.h>
+#include <wtf/HashMap.h>
 #include <wtf/HexNumber.h>
 #include <wtf/text/StringBuilder.h>
+#include <mutex>
 
 namespace WebCore {
 
@@ -1291,6 +1293,246 @@ int PlatformKeyboardEvent::windowsKeyCodeForWPEKeyCode(unsigned keycode)
     return 0;
 }
 
+static const HashMap<int, unsigned>& WPEToWindowsKeyCodeMap()
+{
+    static HashMap<int, unsigned>* result;
+    static std::once_flag once;
+    std::call_once(
+        once,
+        [] {
+            const unsigned WPEKeyCodes[] = {
+                WPE_KEY_Cancel,
+                // FIXME: non-keypad keys should take precedence, so we skip WPE_KEY_KP_*
+                // WPE_KEY_KP_0,
+                // WPE_KEY_KP_1,
+                // WPE_KEY_KP_2,
+                // WPE_KEY_KP_3,
+                // WPE_KEY_KP_4,
+                // WPE_KEY_KP_5,
+                // WPE_KEY_KP_6,
+                // WPE_KEY_KP_7,
+                // WPE_KEY_KP_8,
+                // WPE_KEY_KP_9,
+                // WPE_KEY_KP_Multiply,
+                // WPE_KEY_KP_Add,
+                // WPE_KEY_KP_Subtract,
+                // WPE_KEY_KP_Decimal,
+                // WPE_KEY_KP_Divide,
+                // WPE_KEY_KP_Page_Up,
+                // WPE_KEY_KP_Page_Down,
+                // WPE_KEY_KP_End,
+                // WPE_KEY_KP_Home,
+                // WPE_KEY_KP_Left,
+                // WPE_KEY_KP_Up,
+                // WPE_KEY_KP_Right,
+                // WPE_KEY_KP_Down,
+                WPE_KEY_BackSpace,
+                // WPE_KEY_ISO_Left_Tab,
+                // WPE_KEY_3270_BackTab,
+                WPE_KEY_Tab,
+                WPE_KEY_Clear,
+                // WPE_KEY_ISO_Enter,
+                // WPE_KEY_KP_Enter,
+                WPE_KEY_Return,
+                WPE_KEY_Menu,
+                WPE_KEY_Pause,
+                WPE_KEY_AudioPause,
+                WPE_KEY_Caps_Lock,
+                WPE_KEY_Kana_Lock,
+                WPE_KEY_Kana_Shift,
+                WPE_KEY_Hangul,
+                WPE_KEY_Hangul_Hanja,
+                WPE_KEY_Kanji,
+                WPE_KEY_Escape,
+                WPE_KEY_space,
+                WPE_KEY_Page_Up,
+                WPE_KEY_Page_Down,
+                WPE_KEY_End,
+                WPE_KEY_Home,
+                WPE_KEY_Left,
+                WPE_KEY_Up,
+                WPE_KEY_Right,
+                WPE_KEY_Down,
+                WPE_KEY_Select,
+                WPE_KEY_Print,
+                WPE_KEY_Execute,
+                WPE_KEY_Insert,
+                WPE_KEY_KP_Insert,
+                WPE_KEY_Delete,
+                WPE_KEY_KP_Delete,
+                WPE_KEY_Help,
+                WPE_KEY_0,
+                WPE_KEY_parenright,
+                WPE_KEY_1,
+                WPE_KEY_exclam,
+                WPE_KEY_2,
+                WPE_KEY_at,
+                WPE_KEY_3,
+                WPE_KEY_numbersign,
+                WPE_KEY_4,
+                WPE_KEY_dollar,
+                WPE_KEY_5,
+                WPE_KEY_percent,
+                WPE_KEY_6,
+                WPE_KEY_asciicircum,
+                WPE_KEY_7,
+                WPE_KEY_ampersand,
+                WPE_KEY_8,
+                WPE_KEY_asterisk,
+                WPE_KEY_9,
+                WPE_KEY_parenleft,
+                WPE_KEY_a,
+                WPE_KEY_A,
+                WPE_KEY_b,
+                WPE_KEY_B,
+                WPE_KEY_c,
+                WPE_KEY_C,
+                WPE_KEY_d,
+                WPE_KEY_D,
+                WPE_KEY_e,
+                WPE_KEY_E,
+                WPE_KEY_f,
+                WPE_KEY_F,
+                WPE_KEY_g,
+                WPE_KEY_G,
+                WPE_KEY_h,
+                WPE_KEY_H,
+                WPE_KEY_i,
+                WPE_KEY_I,
+                WPE_KEY_j,
+                WPE_KEY_J,
+                WPE_KEY_k,
+                WPE_KEY_K,
+                WPE_KEY_l,
+                WPE_KEY_L,
+                WPE_KEY_m,
+                WPE_KEY_M,
+                WPE_KEY_n,
+                WPE_KEY_N,
+                WPE_KEY_o,
+                WPE_KEY_O,
+                WPE_KEY_p,
+                WPE_KEY_P,
+                WPE_KEY_q,
+                WPE_KEY_Q,
+                WPE_KEY_r,
+                WPE_KEY_R,
+                WPE_KEY_s,
+                WPE_KEY_S,
+                WPE_KEY_t,
+                WPE_KEY_T,
+                WPE_KEY_u,
+                WPE_KEY_U,
+                WPE_KEY_v,
+                WPE_KEY_V,
+                WPE_KEY_w,
+                WPE_KEY_W,
+                WPE_KEY_x,
+                WPE_KEY_X,
+                WPE_KEY_y,
+                WPE_KEY_Y,
+                WPE_KEY_z,
+                WPE_KEY_Z,
+                WPE_KEY_Meta_L,
+                WPE_KEY_Meta_R,
+                WPE_KEY_Sleep,
+                WPE_KEY_Num_Lock,
+                WPE_KEY_Scroll_Lock,
+                WPE_KEY_Shift_L,
+                WPE_KEY_Shift_R,
+                WPE_KEY_Control_L,
+                WPE_KEY_Control_R,
+                WPE_KEY_Alt_L,
+                WPE_KEY_Alt_R,
+                WPE_KEY_Back,
+                WPE_KEY_Forward,
+                WPE_KEY_Refresh,
+                WPE_KEY_Stop,
+                WPE_KEY_Search,
+                WPE_KEY_Favorites,
+                WPE_KEY_HomePage,
+                WPE_KEY_AudioMute,
+                WPE_KEY_AudioLowerVolume,
+                WPE_KEY_AudioRaiseVolume,
+                WPE_KEY_AudioNext,
+                WPE_KEY_AudioPrev,
+                WPE_KEY_AudioStop,
+                WPE_KEY_AudioMedia,
+                WPE_KEY_semicolon,
+                WPE_KEY_colon,
+                WPE_KEY_plus,
+                WPE_KEY_equal,
+                WPE_KEY_comma,
+                WPE_KEY_less,
+                WPE_KEY_minus,
+                WPE_KEY_underscore,
+                WPE_KEY_period,
+                WPE_KEY_greater,
+                WPE_KEY_slash,
+                WPE_KEY_question,
+                WPE_KEY_asciitilde,
+                WPE_KEY_quoteleft,
+                WPE_KEY_bracketleft,
+                WPE_KEY_braceleft,
+                WPE_KEY_backslash,
+                WPE_KEY_bar,
+                WPE_KEY_bracketright,
+                WPE_KEY_braceright,
+                WPE_KEY_quoteright,
+                WPE_KEY_quotedbl,
+                WPE_KEY_AudioRewind,
+                WPE_KEY_AudioForward,
+                WPE_KEY_AudioPlay,
+                WPE_KEY_F1,
+                WPE_KEY_F2,
+                WPE_KEY_F3,
+                WPE_KEY_F4,
+                WPE_KEY_F5,
+                WPE_KEY_F6,
+                WPE_KEY_F7,
+                WPE_KEY_F8,
+                WPE_KEY_F9,
+                WPE_KEY_F10,
+                WPE_KEY_F11,
+                WPE_KEY_F12,
+                WPE_KEY_F13,
+                WPE_KEY_F14,
+                WPE_KEY_F15,
+                WPE_KEY_F16,
+                WPE_KEY_F17,
+                WPE_KEY_F18,
+                WPE_KEY_F19,
+                WPE_KEY_F20,
+                WPE_KEY_F21,
+                WPE_KEY_F22,
+                WPE_KEY_F23,
+                WPE_KEY_F24,
+                WPE_KEY_VoidSymbol,
+                WPE_KEY_Red,
+                WPE_KEY_Green,
+                WPE_KEY_Yellow,
+                WPE_KEY_Blue,
+                WPE_KEY_PowerOff,
+                WPE_KEY_AudioRecord,
+                WPE_KEY_Display,
+                WPE_KEY_Subtitle,
+                WPE_KEY_Video
+            };
+            result = new HashMap<int, unsigned>();
+            for (unsigned WPEKeyCode : WPEKeyCodes) {
+                int winKeyCode = PlatformKeyboardEvent::windowsKeyCodeForWPEKeyCode(WPEKeyCode);
+                // If several gdk key codes map to the same win key code first one is used.
+                result->add(winKeyCode, WPEKeyCode);
+            }
+        });
+    return *result;
+}
+
+unsigned PlatformKeyboardEvent::WPEKeyCodeForWindowsKeyCode(int keycode)
+{
+    return WPEToWindowsKeyCodeMap().get(keycode);
+}
+
 String PlatformKeyboardEvent::singleCharacterString(unsigned val)
 {
     switch (val) {
diff --git a/Source/WebCore/platform/network/NetworkStateNotifier.h b/Source/WebCore/platform/network/NetworkStateNotifier.h
index 87930048f4fd18d6098af7de4da25be532df5931..2bb2afcf9473b0d5d97efbe18dd7b8145bc5f932 100644
--- a/Source/WebCore/platform/network/NetworkStateNotifier.h
+++ b/Source/WebCore/platform/network/NetworkStateNotifier.h
@@ -72,6 +72,7 @@ private:
 #endif
 
     Optional<bool> m_isOnLine;
+    Optional<bool> m_emulatedIsOnLine;
     Vector<WTF::Function<void(bool)>> m_listeners;
     Timer m_updateStateTimer;
 
diff --git a/Source/WebCore/platform/win/KeyEventWin.cpp b/Source/WebCore/platform/win/KeyEventWin.cpp
index 44737686187a06a92c408ea60b63a48ac8481334..c754a763688b52e7ddd47493296ef9b0c6adc527 100644
--- a/Source/WebCore/platform/win/KeyEventWin.cpp
+++ b/Source/WebCore/platform/win/KeyEventWin.cpp
@@ -239,10 +239,16 @@ PlatformKeyboardEvent::PlatformKeyboardEvent(HWND, WPARAM code, LPARAM keyData,
 {
 }
 
-void PlatformKeyboardEvent::disambiguateKeyDownEvent(Type, bool)
+void PlatformKeyboardEvent::disambiguateKeyDownEvent(Type type, bool backwardsCompatibility)
 {
-    // No KeyDown events on Windows to disambiguate.
-    ASSERT_NOT_REACHED();
+    m_type = type;
+    if (type == PlatformEvent::RawKeyDown) {
+        m_text = String();
+        m_unmodifiedText = String();
+    } else {
+        m_keyIdentifier = String();
+        m_windowsVirtualKeyCode = 0;
+    }
 }
 
 bool PlatformKeyboardEvent::currentCapsLockState()
diff --git a/Source/WebKit/NetworkProcess/NetworkProcess.cpp b/Source/WebKit/NetworkProcess/NetworkProcess.cpp
index 34dcb2bf24ea97333e1a3d0d768b0b3b5f7acd92..c774fd25734d6842ddab93b354b521f33b16d13d 100644
--- a/Source/WebKit/NetworkProcess/NetworkProcess.cpp
+++ b/Source/WebKit/NetworkProcess/NetworkProcess.cpp
@@ -26,7 +26,6 @@
 
 #include "config.h"
 #include "NetworkProcess.h"
-
 #include "ArgumentCoders.h"
 #include "Attachment.h"
 #include "AuthenticationManager.h"
@@ -592,6 +591,35 @@ void NetworkProcess::destroySession(PAL::SessionID sessionID)
     m_storageManagerSet->remove(sessionID);
 }
 
+void NetworkProcess::getAllCookies(PAL::SessionID sessionID, CompletionHandler<void(Vector<WebCore::Cookie>&&)>&& completionHandler)
+{
+    if (auto* networkStorageSession = storageSession(sessionID)) {
+        completionHandler(networkStorageSession->getAllCookies());
+        return;
+    }
+    completionHandler({ });
+}
+
+void NetworkProcess::setCookies(PAL::SessionID sessionID, Vector<WebCore::Cookie> cookies, CompletionHandler<void(bool)>&& completionHandler) {
+    if (auto* networkStorageSession = storageSession(sessionID)) {
+        for (auto cookie : cookies)
+            networkStorageSession->setCookie(cookie);
+        completionHandler(true);
+        return;
+    }
+    completionHandler(false);
+}
+
+void NetworkProcess::deleteAllCookies(PAL::SessionID sessionID, CompletionHandler<void(bool)>&& completionHandler)
+{
+    if (auto* networkStorageSession = storageSession(sessionID)) {
+        networkStorageSession->deleteAllCookies();
+        completionHandler(true);
+        return;
+    }
+    completionHandler(false);
+}
+
 #if ENABLE(RESOURCE_LOAD_STATISTICS)
 void NetworkProcess::dumpResourceLoadStatistics(PAL::SessionID sessionID, CompletionHandler<void(String)>&& completionHandler)
 {
diff --git a/Source/WebKit/NetworkProcess/NetworkProcess.h b/Source/WebKit/NetworkProcess/NetworkProcess.h
index 342d6a6be93265425d5dd29d789b6e51818ce341..0d5de105f6246787a72ea13a3aab0ec3d1e55aaa 100644
--- a/Source/WebKit/NetworkProcess/NetworkProcess.h
+++ b/Source/WebKit/NetworkProcess/NetworkProcess.h
@@ -74,6 +74,7 @@ class SessionID;
 
 namespace WebCore {
 class CertificateInfo;
+struct Cookie;
 class CurlProxySettings;
 class DownloadID;
 class ProtectionSpace;
@@ -202,6 +203,10 @@ public:
 
     void addWebsiteDataStore(WebsiteDataStoreParameters&&);
 
+    void getAllCookies(PAL::SessionID, CompletionHandler<void(Vector<WebCore::Cookie>&&)>&&);
+    void setCookies(PAL::SessionID, Vector<WebCore::Cookie>, CompletionHandler<void(bool)>&&);
+    void deleteAllCookies(PAL::SessionID, CompletionHandler<void(bool)>&&);
+
 #if ENABLE(RESOURCE_LOAD_STATISTICS)
     void clearPrevalentResource(PAL::SessionID, const RegistrableDomain&, CompletionHandler<void()>&&);
     void clearUserInteraction(PAL::SessionID, const RegistrableDomain&, CompletionHandler<void()>&&);
@@ -308,6 +313,7 @@ public:
 
 #if PLATFORM(COCOA)
     NetworkHTTPSUpgradeChecker& networkHTTPSUpgradeChecker();
+    bool ignoreTLSErrors() const { return m_ignoreTLSErrors; }
 #endif
 
     const String& uiProcessBundleIdentifier() const { return m_uiProcessBundleIdentifier; }
@@ -421,8 +427,10 @@ private:
     void syncAllCookies();
     void didSyncAllCookies();
 
-#if USE(SOUP)
+#if PLATFORM(COCOA) || USE(CURL) || USE(SOUP)
     void setIgnoreTLSErrors(bool);
+#endif
+#if USE(SOUP)
     void userPreferredLanguagesChanged(const Vector<String>&);
     void setNetworkProxySettings(const WebCore::SoupNetworkProxySettings&);
 #endif
@@ -569,6 +577,7 @@ private:
 
 #if PLATFORM(COCOA)
     std::unique_ptr<NetworkHTTPSUpgradeChecker> m_networkHTTPSUpgradeChecker;
+    bool m_ignoreTLSErrors { false };
 #endif
 
 #if ENABLE(RESOURCE_LOAD_STATISTICS)
diff --git a/Source/WebKit/NetworkProcess/NetworkProcess.messages.in b/Source/WebKit/NetworkProcess/NetworkProcess.messages.in
index c8d008fd91eefc02d7be1db5e8a47bb39380367d..5cfb5c6fcaca5963b09b3467a5638be18cdf350b 100644
--- a/Source/WebKit/NetworkProcess/NetworkProcess.messages.in
+++ b/Source/WebKit/NetworkProcess/NetworkProcess.messages.in
@@ -27,8 +27,10 @@ messages -> NetworkProcess LegacyReceiver {
     # Creates a connection for communication with a WebProcess
     CreateNetworkConnectionToWebProcess(WebCore::ProcessIdentifier processIdentifier, PAL::SessionID sessionID) -> (Optional<IPC::Attachment> connectionIdentifier, enum:uint8_t WebCore::HTTPCookieAcceptPolicy cookieAcceptPolicy) Async
 
-#if USE(SOUP)
+#if USE(SOUP) || PLATFORM(COCOA) || USE(CURL)
     SetIgnoreTLSErrors(bool ignoreTLSErrors)
+#endif
+#if USE(SOUP)
     UserPreferredLanguagesChanged(Vector<String> languages)
     SetNetworkProxySettings(struct WebCore::SoupNetworkProxySettings settings)
     PrefetchDNS(String hostname)
@@ -82,6 +84,10 @@ messages -> NetworkProcess LegacyReceiver {
 
     PreconnectTo(PAL::SessionID sessionID, URL url, String userAgent, enum:uint8_t WebCore::StoredCredentialsPolicy storedCredentialsPolicy);
 
+    GetAllCookies(PAL::SessionID sessionID) -> (Vector<WebCore::Cookie> cookies) Async
+    SetCookies(PAL::SessionID sessionID, Vector<WebCore::Cookie> cookies) -> (bool success) Async
+    DeleteAllCookies(PAL::SessionID sessionID) -> (bool success) Async
+
 #if ENABLE(RESOURCE_LOAD_STATISTICS)
     ClearPrevalentResource(PAL::SessionID sessionID, WebCore::RegistrableDomain resourceDomain) -> () Async
     ClearUserInteraction(PAL::SessionID sessionID, WebCore::RegistrableDomain resourceDomain) -> () Async
diff --git a/Source/WebKit/NetworkProcess/NetworkProcessCreationParameters.h b/Source/WebKit/NetworkProcess/NetworkProcessCreationParameters.h
index bdc2cae74892db1b0a26d22afbe2a4bb7a6c0ab0..7c45a71befbcd531e724a816d606f81fe6061a2f 100644
--- a/Source/WebKit/NetworkProcess/NetworkProcessCreationParameters.h
+++ b/Source/WebKit/NetworkProcess/NetworkProcessCreationParameters.h
@@ -74,9 +74,9 @@ struct NetworkProcessCreationParameters {
 
     WebsiteDataStoreParameters defaultDataStoreParameters;
     
+    bool ignoreTLSErrors { false };
 #if USE(SOUP)
     WebCore::HTTPCookieAcceptPolicy cookieAcceptPolicy { WebCore::HTTPCookieAcceptPolicy::AlwaysAccept };
-    bool ignoreTLSErrors { false };
     Vector<String> languages;
     WebCore::SoupNetworkProxySettings proxySettings;
 #endif
diff --git a/Source/WebKit/NetworkProcess/cocoa/NetworkProcessCocoa.mm b/Source/WebKit/NetworkProcess/cocoa/NetworkProcessCocoa.mm
index 6416bcfe97bf44a231f0691c5ce97fba791df526..58aa3dd33f2f96c045a2b725e74c3da2a4a6ce80 100644
--- a/Source/WebKit/NetworkProcess/cocoa/NetworkProcessCocoa.mm
+++ b/Source/WebKit/NetworkProcess/cocoa/NetworkProcessCocoa.mm
@@ -89,6 +89,8 @@ void NetworkProcess::platformInitializeNetworkProcessCocoa(const NetworkProcessC
 #endif
 #endif
 
+    setIgnoreTLSErrors(parameters.ignoreTLSErrors);
+
     _CFNetworkSetATSContext(parameters.networkATSContext.get());
 
     m_uiProcessBundleIdentifier = parameters.uiProcessBundleIdentifier;
@@ -209,6 +211,7 @@ void NetworkProcess::syncAllCookies()
     });
 }
 
+
 #if HAVE(FOUNDATION_WITH_SAVE_COOKIES_WITH_COMPLETION_HANDLER)
 static void saveCookies(NSHTTPCookieStorage *cookieStorage, CompletionHandler<void()>&& completionHandler)
 {
@@ -239,6 +242,11 @@ void NetworkProcess::platformSyncAllCookies(CompletionHandler<void()>&& completi
     ALLOW_DEPRECATED_DECLARATIONS_END
 }
 
+void NetworkProcess::setIgnoreTLSErrors(bool ignoreTLSErrors)
+{
+    m_ignoreTLSErrors = ignoreTLSErrors;
+}
+
 void NetworkProcess::platformPrepareToSuspend(CompletionHandler<void()>&& completionHandler)
 {
     completionHandler();
diff --git a/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.h b/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.h
index da61fcc03de3a08e41bd1f57b7497303e6ac7913..031361c5013f3172da2c33dccdef5cbacf58937f 100644
--- a/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.h
+++ b/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.h
@@ -77,7 +77,7 @@ public:
     const String& dataConnectionServiceType() const;
 #endif
 
-    static bool allowsSpecificHTTPSCertificateForHost(const WebCore::AuthenticationChallenge&);
+    bool allowsSpecificHTTPSCertificateForHost(const WebCore::AuthenticationChallenge&);
 
     void continueDidReceiveChallenge(SessionWrapper&, const WebCore::AuthenticationChallenge&, NegotiatedLegacyTLS, NetworkDataTaskCocoa::TaskIdentifier, NetworkDataTaskCocoa*, CompletionHandler<void(WebKit::AuthenticationChallengeDisposition, const WebCore::Credential&)>&&);
 
diff --git a/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.mm b/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.mm
index 92429dee3bef49cc9110f9dcaace7f490d236c4c..0a75f997d2d20d3b142d8d4c64ef8e6233efc6d4 100644
--- a/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.mm
+++ b/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.mm
@@ -651,7 +651,7 @@ static inline void processServerTrustEvaluation(NetworkSessionCocoa& session, Se
     NegotiatedLegacyTLS negotiatedLegacyTLS = NegotiatedLegacyTLS::No;
 
     if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
-        if (NetworkSessionCocoa::allowsSpecificHTTPSCertificateForHost(challenge))
+        if (sessionCocoa->allowsSpecificHTTPSCertificateForHost(challenge))
             return completionHandler(NSURLSessionAuthChallengeUseCredential, [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust]);
 
 #if HAVE(TLS_PROTOCOL_VERSION_T)
@@ -1363,6 +1363,9 @@ static bool certificatesMatch(SecTrustRef trust1, SecTrustRef trust2)
 
 bool NetworkSessionCocoa::allowsSpecificHTTPSCertificateForHost(const WebCore::AuthenticationChallenge& challenge)
 {
+    if (networkProcess().ignoreTLSErrors())
+        return true;
+
     const String& host = challenge.protectionSpace().host();
     NSArray *certificates = [NSURLRequest allowsSpecificHTTPSCertificateForHost:host];
     if (!certificates)
diff --git a/Source/WebKit/NetworkProcess/curl/NetworkProcessCurl.cpp b/Source/WebKit/NetworkProcess/curl/NetworkProcessCurl.cpp
index 5be170266f45b8bf72ef56b10087cb59bb56dba9..24f8885a0054c1a64cb7deebb00bb4421c56a858 100644
--- a/Source/WebKit/NetworkProcess/curl/NetworkProcessCurl.cpp
+++ b/Source/WebKit/NetworkProcess/curl/NetworkProcessCurl.cpp
@@ -94,4 +94,9 @@ void NetworkProcess::setNetworkProxySettings(PAL::SessionID sessionID, WebCore::
         ASSERT_NOT_REACHED();
 }
 
+void NetworkProcess::setIgnoreTLSErrors(bool ignoreTLSErrors)
+{
+    CurlContext::singleton().sslHandle().setIgnoreSSLErrors(ignoreTLSErrors);
+}
+
 } // namespace WebKit
diff --git a/Source/WebKit/PlatformWPE.cmake b/Source/WebKit/PlatformWPE.cmake
index 963518a05c4ad1a4690048341104022504e04651..e6800b106c40fec6cd80415498a6bddfee1c17ac 100644
--- a/Source/WebKit/PlatformWPE.cmake
+++ b/Source/WebKit/PlatformWPE.cmake
@@ -249,6 +249,7 @@ list(APPEND WebKit_INCLUDE_DIRECTORIES
     "${WEBKIT_DIR}/UIProcess/API/wpe"
     "${WEBKIT_DIR}/UIProcess/CoordinatedGraphics"
     "${WEBKIT_DIR}/UIProcess/geoclue"
+    "${WEBKIT_DIR}/UIProcess/glib"
     "${WEBKIT_DIR}/UIProcess/gstreamer"
     "${WEBKIT_DIR}/UIProcess/linux"
     "${WEBKIT_DIR}/UIProcess/soup"
diff --git a/Source/WebKit/PlatformWin.cmake b/Source/WebKit/PlatformWin.cmake
index 5d9628d3180e8b14ce3c1356437c5a86722cd99e..bcae76dc863599acf74c4b2e3f3d49bf67ef8e12 100644
--- a/Source/WebKit/PlatformWin.cmake
+++ b/Source/WebKit/PlatformWin.cmake
@@ -56,8 +56,12 @@ list(APPEND WebKit_SOURCES
 
     UIProcess/WebsiteData/win/WebsiteDataStoreWin.cpp
 
+    UIProcess/win/InspectorTargetProxyWin.cpp
+    UIProcess/win/InspectorBrowserAgentClientWin.cpp
     UIProcess/win/PageClientImpl.cpp
     UIProcess/win/WebContextMenuProxyWin.cpp
+    UIProcess/win/WebPageInspectorEmulationAgentWin.cpp
+    UIProcess/win/WebPageInspectorInputAgentWin.cpp
     UIProcess/win/WebPageProxyWin.cpp
     UIProcess/win/WebPopupMenuProxyWin.cpp
     UIProcess/win/WebProcessPoolWin.cpp
diff --git a/Source/WebKit/Shared/API/c/wpe/WebKit.h b/Source/WebKit/Shared/API/c/wpe/WebKit.h
index 898e30b370db8176e886fbbde0cd960e38a64818..74945e06fac0eb14936578de6a599a123364a63a 100644
--- a/Source/WebKit/Shared/API/c/wpe/WebKit.h
+++ b/Source/WebKit/Shared/API/c/wpe/WebKit.h
@@ -78,6 +78,7 @@
 // From Source/WebKit/UIProcess/API/C
 #include <WebKit/WKBackForwardListItemRef.h>
 #include <WebKit/WKBackForwardListRef.h>
+#include <WebKit/WKBrowserInspector.h>
 #include <WebKit/WKContext.h>
 #include <WebKit/WKContextConfigurationRef.h>
 #include <WebKit/WKCredential.h>
diff --git a/Source/WebKit/Shared/NativeWebKeyboardEvent.h b/Source/WebKit/Shared/NativeWebKeyboardEvent.h
index f08c19fb95ec8c8cca8f4ca2aa4049885637febf..c09e35e1b4fbf95b31f8d890bf09231055e4373a 100644
--- a/Source/WebKit/Shared/NativeWebKeyboardEvent.h
+++ b/Source/WebKit/Shared/NativeWebKeyboardEvent.h
@@ -34,6 +34,7 @@
 #if USE(APPKIT)
 #include <wtf/RetainPtr.h>
 OBJC_CLASS NSView;
+OBJC_CLASS NSEvent;
 
 namespace WebCore {
 struct CompositionUnderline;
@@ -67,18 +68,34 @@ public:
 #if USE(APPKIT)
     // FIXME: Share iOS's HandledByInputMethod enum here instead of passing a boolean.
     NativeWebKeyboardEvent(NSEvent *, bool handledByInputMethod, bool replacesSoftSpace, const Vector<WebCore::KeypressCommand>&);
+    NativeWebKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier> modifiers, WallTime timestamp, Vector<WebCore::KeypressCommand>&& commands)
+        : WebKeyboardEvent(type, text, unmodifiedText, key, code, keyIdentifier, windowsVirtualKeyCode, nativeVirtualKeyCode, isAutoRepeat, isKeypad, isSystemKey, modifiers, timestamp, WTFMove(commands))
+    {
+    }
 #elif PLATFORM(GTK)
     NativeWebKeyboardEvent(const NativeWebKeyboardEvent&);
     enum class HandledByInputMethod : bool { No, Yes };
     NativeWebKeyboardEvent(GdkEvent*, const String&, HandledByInputMethod, Optional<Vector<WebCore::CompositionUnderline>>&&, Optional<EditingRange>&&, Vector<String>&& commands);
+    NativeWebKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier> modifiers, WallTime timestamp, Vector<String>&& commands)
+        : WebKeyboardEvent(type, text, unmodifiedText, key, code, keyIdentifier, windowsVirtualKeyCode, nativeVirtualKeyCode, isAutoRepeat, isKeypad, isSystemKey, modifiers, timestamp, WTFMove(commands))
+    {
+    }
 #elif PLATFORM(IOS_FAMILY)
     enum class HandledByInputMethod : bool { No, Yes };
     NativeWebKeyboardEvent(::WebEvent *, HandledByInputMethod);
 #elif USE(LIBWPE)
     enum class HandledByInputMethod : bool { No, Yes };
     NativeWebKeyboardEvent(struct wpe_input_keyboard_event*, const String&, HandledByInputMethod, Optional<Vector<WebCore::CompositionUnderline>>&&, Optional<EditingRange>&&);
+    NativeWebKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier> modifiers, WallTime timestamp)
+        : WebKeyboardEvent(type, text, unmodifiedText, key, code, keyIdentifier, windowsVirtualKeyCode, nativeVirtualKeyCode, isAutoRepeat, isKeypad, isSystemKey, modifiers, timestamp)
+    {
+    }
 #elif PLATFORM(WIN)
     NativeWebKeyboardEvent(HWND, UINT message, WPARAM, LPARAM, Vector<MSG>&& pendingCharEvents);
+    NativeWebKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier> modifiers, WallTime timestamp)
+        : WebKeyboardEvent(type, text, unmodifiedText, key, code, keyIdentifier, windowsVirtualKeyCode, nativeVirtualKeyCode, isAutoRepeat, isKeypad, isSystemKey, modifiers, timestamp)
+    {
+    }
 #endif
 
 #if USE(APPKIT)
diff --git a/Source/WebKit/Shared/NativeWebMouseEvent.h b/Source/WebKit/Shared/NativeWebMouseEvent.h
index 0fa557e9faa34ba81a7a4f7da5e32f30cbfad5d2..4f06afeb895fb1231d87e4304a4b588cd326944c 100644
--- a/Source/WebKit/Shared/NativeWebMouseEvent.h
+++ b/Source/WebKit/Shared/NativeWebMouseEvent.h
@@ -70,6 +70,11 @@ public:
     NativeWebMouseEvent(HWND, UINT message, WPARAM, LPARAM, bool);
 #endif
 
+#if PLATFORM(GTK) || USE(LIBWPE) || PLATFORM(WIN)
+    NativeWebMouseEvent(Type type, Button button, unsigned short buttons, const WebCore::IntPoint& position, const WebCore::IntPoint& globalPosition, float deltaX, float deltaY, float deltaZ, int clickCount, OptionSet<Modifier> modifiers, WallTime timestamp)
+       : WebMouseEvent(type, button, buttons, position, globalPosition, deltaX, deltaY, deltaZ, clickCount, modifiers, timestamp) { }
+#endif
+
 #if USE(APPKIT)
     NSEvent* nativeEvent() const { return m_nativeEvent.get(); }
 #elif PLATFORM(GTK)
diff --git a/Source/WebKit/Shared/WebEvent.h b/Source/WebKit/Shared/WebEvent.h
index 224ef51567fdf5eb7321a3411faccd283b5b2813..7c102952d5821486f0c6a0af0b8d3286ace96b93 100644
--- a/Source/WebKit/Shared/WebEvent.h
+++ b/Source/WebKit/Shared/WebEvent.h
@@ -37,6 +37,7 @@
 #include <WebCore/IntSize.h>
 #include <WebCore/KeypressCommand.h>
 #include <wtf/OptionSet.h>
+#include <wtf/RefCounted.h>
 #include <wtf/WallTime.h>
 #include <wtf/text/WTFString.h>
 
@@ -252,14 +253,18 @@ public:
 
 #if USE(APPKIT)
     WebKeyboardEvent(Type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, int macCharCode, bool handledByInputMethod, const Vector<WebCore::KeypressCommand>&, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier>, WallTime timestamp);
+    WebKeyboardEvent(Type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier>, WallTime timestamp, Vector<WebCore::KeypressCommand>&& commands);
 #elif PLATFORM(GTK)
     WebKeyboardEvent(Type, const String& text, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool handledByInputMethod, Optional<Vector<WebCore::CompositionUnderline>>&&, Optional<EditingRange>&&, Vector<String>&& commands, bool isKeypad, OptionSet<Modifier>, WallTime timestamp);
+    WebKeyboardEvent(Type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier>, WallTime timestamp, Vector<String>&& commands);
 #elif PLATFORM(IOS_FAMILY)
     WebKeyboardEvent(Type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, int macCharCode, bool handledByInputMethod, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier>, WallTime timestamp);
 #elif USE(LIBWPE)
     WebKeyboardEvent(Type, const String& text, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool handledByInputMethod, Optional<Vector<WebCore::CompositionUnderline>>&&, Optional<EditingRange>&&, bool isKeypad, OptionSet<Modifier>, WallTime timestamp);
+    WebKeyboardEvent(Type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier>, WallTime timestamp);
 #else
     WebKeyboardEvent(Type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, int macCharCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier>, WallTime timestamp);
+    WebKeyboardEvent(Type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier>, WallTime timestamp);
 #endif
 
     const String& text() const { return m_text; }
@@ -301,7 +306,7 @@ private:
     int32_t m_nativeVirtualKeyCode;
     int32_t m_macCharCode;
 #if USE(APPKIT) || USE(UIKIT_KEYBOARD_ADDITIONS) || PLATFORM(GTK) || USE(LIBWPE)
-    bool m_handledByInputMethod;
+    bool m_handledByInputMethod = false;
 #endif
 #if PLATFORM(GTK) || USE(LIBWPE)
     Optional<Vector<WebCore::CompositionUnderline>> m_preeditUnderlines;
diff --git a/Source/WebKit/Shared/WebKeyboardEvent.cpp b/Source/WebKit/Shared/WebKeyboardEvent.cpp
index cccb560418f32fad40587ac083b95f398eb1399d..f6b0aee44e5f12055dd14ad0636d780d2d4ece5d 100644
--- a/Source/WebKit/Shared/WebKeyboardEvent.cpp
+++ b/Source/WebKit/Shared/WebKeyboardEvent.cpp
@@ -35,6 +35,7 @@ WebKeyboardEvent::WebKeyboardEvent()
 {
 }
 
+
 #if USE(APPKIT)
 
 WebKeyboardEvent::WebKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, int macCharCode, bool handledByInputMethod, const Vector<WebCore::KeypressCommand>& commands, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier> modifiers, WallTime timestamp)
@@ -56,6 +57,24 @@ WebKeyboardEvent::WebKeyboardEvent(Type type, const String& text, const String&
     ASSERT(isKeyboardEventType(type));
 }
 
+WebKeyboardEvent::WebKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier> modifiers, WallTime timestamp, Vector<WebCore::KeypressCommand>&& commands)
+    : WebEvent(type, modifiers, timestamp)
+    , m_text(text)
+    , m_unmodifiedText(text)
+    , m_key(key)
+    , m_code(code)
+    , m_keyIdentifier(keyIdentifier)
+    , m_windowsVirtualKeyCode(windowsVirtualKeyCode)
+    , m_nativeVirtualKeyCode(nativeVirtualKeyCode)
+    , m_macCharCode(0)
+    , m_commands(WTFMove(commands))
+    , m_isAutoRepeat(isAutoRepeat)
+    , m_isKeypad(isKeypad)
+    , m_isSystemKey(isSystemKey)
+{
+    ASSERT(isKeyboardEventType(type));
+}
+
 #elif PLATFORM(GTK)
 
 WebKeyboardEvent::WebKeyboardEvent(Type type, const String& text, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool handledByInputMethod, Optional<Vector<WebCore::CompositionUnderline>>&& preeditUnderlines, Optional<EditingRange>&& preeditSelectionRange, Vector<String>&& commands, bool isKeypad, OptionSet<Modifier> modifiers, WallTime timestamp)
@@ -79,6 +98,24 @@ WebKeyboardEvent::WebKeyboardEvent(Type type, const String& text, const String&
     ASSERT(isKeyboardEventType(type));
 }
 
+WebKeyboardEvent::WebKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier> modifiers, WallTime timestamp, Vector<String>&& commands)
+    : WebEvent(type, modifiers, timestamp)
+    , m_text(text)
+    , m_unmodifiedText(text)
+    , m_key(key)
+    , m_code(code)
+    , m_keyIdentifier(keyIdentifier)
+    , m_windowsVirtualKeyCode(windowsVirtualKeyCode)
+    , m_nativeVirtualKeyCode(nativeVirtualKeyCode)
+    , m_macCharCode(0)
+    , m_commands(WTFMove(commands))
+    , m_isAutoRepeat(isAutoRepeat)
+    , m_isKeypad(isKeypad)
+    , m_isSystemKey(isSystemKey)
+{
+    ASSERT(isKeyboardEventType(type));
+}
+
 #elif PLATFORM(IOS_FAMILY)
 
 WebKeyboardEvent::WebKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, int macCharCode, bool handledByInputMethod, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier> modifiers, WallTime timestamp)
@@ -144,6 +181,27 @@ WebKeyboardEvent::WebKeyboardEvent(Type type, const String& text, const String&
 
 #endif
 
+#if PLATFORM(WIN) || USE(LIBWPE)
+
+WebKeyboardEvent::WebKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<Modifier> modifiers, WallTime timestamp)
+    : WebEvent(type, modifiers, timestamp)
+    , m_text(text)
+    , m_unmodifiedText(text)
+    , m_key(key)
+    , m_code(code)
+    , m_keyIdentifier(keyIdentifier)
+    , m_windowsVirtualKeyCode(windowsVirtualKeyCode)
+    , m_nativeVirtualKeyCode(nativeVirtualKeyCode)
+    , m_macCharCode(0)
+    , m_isAutoRepeat(isAutoRepeat)
+    , m_isKeypad(isKeypad)
+    , m_isSystemKey(isSystemKey)
+{
+    ASSERT(isKeyboardEventType(type));
+}
+
+#endif
+
 WebKeyboardEvent::~WebKeyboardEvent()
 {
 }
diff --git a/Source/WebKit/Shared/WebPageCreationParameters.cpp b/Source/WebKit/Shared/WebPageCreationParameters.cpp
index 6c99391270afb2b0500c088d86907adfb86d69d2..6dc325199dafc685e53709f997abd4bbd1f461ae 100644
--- a/Source/WebKit/Shared/WebPageCreationParameters.cpp
+++ b/Source/WebKit/Shared/WebPageCreationParameters.cpp
@@ -145,6 +145,8 @@ void WebPageCreationParameters::encode(IPC::Encoder& encoder) const
     encoder << shouldCaptureVideoInGPUProcess;
     encoder << shouldCaptureDisplayInUIProcess;
 
+    encoder << shouldPauseInInspectorWhenShown;
+
 #if PLATFORM(GTK)
     encoder << themeName;
 #endif
@@ -456,6 +458,9 @@ Optional<WebPageCreationParameters> WebPageCreationParameters::decode(IPC::Decod
     if (!decoder.decode(parameters.shouldCaptureDisplayInUIProcess))
         return WTF::nullopt;
 
+    if (!decoder.decode(parameters.shouldPauseInInspectorWhenShown))
+        return WTF::nullopt;
+
 #if PLATFORM(GTK)
     if (!decoder.decode(parameters.themeName))
         return WTF::nullopt;
diff --git a/Source/WebKit/Shared/WebPageCreationParameters.h b/Source/WebKit/Shared/WebPageCreationParameters.h
index 6dec8d54440432d6cb6fba57d881e33d18e641e8..980c962c078eda7458365067e81db4e60ff1c4fc 100644
--- a/Source/WebKit/Shared/WebPageCreationParameters.h
+++ b/Source/WebKit/Shared/WebPageCreationParameters.h
@@ -216,6 +216,8 @@ struct WebPageCreationParameters {
     bool shouldCaptureVideoInGPUProcess { false };
     bool shouldCaptureDisplayInUIProcess { false };
 
+    bool shouldPauseInInspectorWhenShown { false };
+
 #if PLATFORM(GTK)
     String themeName;
 #endif
diff --git a/Source/WebKit/Shared/gtk/NativeWebKeyboardEventGtk.cpp b/Source/WebKit/Shared/gtk/NativeWebKeyboardEventGtk.cpp
index 2357f3d58415fae78e48b0f8a25bddad85c786bf..f3941a74922f5a0a3bf59a11cd4c42fbfd33d0af 100644
--- a/Source/WebKit/Shared/gtk/NativeWebKeyboardEventGtk.cpp
+++ b/Source/WebKit/Shared/gtk/NativeWebKeyboardEventGtk.cpp
@@ -40,7 +40,7 @@ NativeWebKeyboardEvent::NativeWebKeyboardEvent(GdkEvent* event, const String& te
 }
 
 NativeWebKeyboardEvent::NativeWebKeyboardEvent(const NativeWebKeyboardEvent& event)
-    : WebKeyboardEvent(WebEventFactory::createWebKeyboardEvent(event.nativeEvent(), event.text(), event.handledByInputMethod(), Optional<Vector<WebCore::CompositionUnderline>>(event.preeditUnderlines()), Optional<EditingRange>(event.preeditSelectionRange()), Vector<String>(event.commands())))
+    : WebKeyboardEvent(event)
     , m_nativeEvent(gdk_event_copy(event.nativeEvent()))
 {
 }
diff --git a/Source/WebKit/Shared/gtk/NativeWebMouseEventGtk.cpp b/Source/WebKit/Shared/gtk/NativeWebMouseEventGtk.cpp
index 58e37fe3827cdb08d36ef0c85b8d4a968dee001a..429d245ea99fdee1b598a5caf51de8ce4b47fb02 100644
--- a/Source/WebKit/Shared/gtk/NativeWebMouseEventGtk.cpp
+++ b/Source/WebKit/Shared/gtk/NativeWebMouseEventGtk.cpp
@@ -38,8 +38,8 @@ NativeWebMouseEvent::NativeWebMouseEvent(GdkEvent* event, int eventClickCount, O
 }
 
 NativeWebMouseEvent::NativeWebMouseEvent(const NativeWebMouseEvent& event)
-    : WebMouseEvent(WebEventFactory::createWebMouseEvent(event.nativeEvent(), event.clickCount(), WebCore::IntPoint(event.deltaX(), event.deltaY())))
-    , m_nativeEvent(gdk_event_copy(event.nativeEvent()))
+    : WebMouseEvent(event)
+    , m_nativeEvent(event.nativeEvent() ? gdk_event_copy(event.nativeEvent()) : nullptr)
 {
 }
 
diff --git a/Source/WebKit/Shared/ios/WebPlatformTouchPointIOS.cpp b/Source/WebKit/Shared/ios/WebPlatformTouchPointIOS.cpp
index 7b5eb372880d8662544334cd4697276d543de45b..ba06ecbb2cf5088a4c8c0824b50cb7797605dc57 100644
--- a/Source/WebKit/Shared/ios/WebPlatformTouchPointIOS.cpp
+++ b/Source/WebKit/Shared/ios/WebPlatformTouchPointIOS.cpp
@@ -26,7 +26,7 @@
 #include "config.h"
 #include "WebEvent.h"
 
-#if ENABLE(TOUCH_EVENTS)
+#if ENABLE(TOUCH_EVENTS) && PLATFORM(IOS_FAMILY)
 
 #include "WebCoreArgumentCoders.h"
 
@@ -79,4 +79,4 @@ Optional<WebPlatformTouchPoint> WebPlatformTouchPoint::decode(IPC::Decoder& deco
 
 } // namespace WebKit
 
-#endif // ENABLE(TOUCH_EVENTS)
+#endif // ENABLE(TOUCH_EVENTS) && PLATFORM(IOS_FAMILY)
diff --git a/Source/WebKit/Shared/ios/WebTouchEventIOS.cpp b/Source/WebKit/Shared/ios/WebTouchEventIOS.cpp
index 45a56eb3b0fda13c3b78d57594a0092e4e1866f6..5e29e15813be6abe82790e6a98d3947e7a6fae44 100644
--- a/Source/WebKit/Shared/ios/WebTouchEventIOS.cpp
+++ b/Source/WebKit/Shared/ios/WebTouchEventIOS.cpp
@@ -26,7 +26,7 @@
 #include "config.h"
 #include "WebEvent.h"
 
-#if ENABLE(TOUCH_EVENTS)
+#if ENABLE(TOUCH_EVENTS) && PLATFORM(IOS_FAMILY)
 
 #include "ArgumentCoders.h"
 #include "WebCoreArgumentCoders.h"
@@ -71,4 +71,4 @@ bool WebTouchEvent::decode(IPC::Decoder& decoder, WebTouchEvent& result)
 
 } // namespace WebKit
 
-#endif // ENABLE(TOUCH_EVENTS)
+#endif // ENABLE(TOUCH_EVENTS) && PLATFORM(IOS_FAMILY)
diff --git a/Source/WebKit/Shared/win/WebEventFactory.cpp b/Source/WebKit/Shared/win/WebEventFactory.cpp
index 88d53d236cd6d62735f03678a04ca9c198dddacb..b8f8efc57ab00dc5725660c5a8ad56a3e6384de5 100644
--- a/Source/WebKit/Shared/win/WebEventFactory.cpp
+++ b/Source/WebKit/Shared/win/WebEventFactory.cpp
@@ -473,7 +473,7 @@ WebKeyboardEvent WebEventFactory::createWebKeyboardEvent(HWND hwnd, UINT message
 }
 
 #if ENABLE(TOUCH_EVENTS)
-WebTouchEvent WebEventFactory::createWebTouchEvent(const GdkEvent* event, Vector<WebPlatformTouchPoint>&& touchPoints)
+WebTouchEvent WebEventFactory::createWebTouchEvent()
 {
     return WebTouchEvent();
 }
diff --git a/Source/WebKit/Sources.txt b/Source/WebKit/Sources.txt
index a5d0be14271f6306f836b8fdbd7d420f295246ea..8cd997ea1d527a14b44f919ab1ae60dabcb7beb7 100644
--- a/Source/WebKit/Sources.txt
+++ b/Source/WebKit/Sources.txt
@@ -262,16 +262,21 @@ Shared/WebsiteData/WebsiteData.cpp
 
 UIProcess/AuxiliaryProcessProxy.cpp
 UIProcess/BackgroundProcessResponsivenessTimer.cpp
+UIProcess/BrowserInspectorController.cpp
+UIProcess/BrowserInspectorPipe.cpp
 UIProcess/DeviceIdHashSaltStorage.cpp
 UIProcess/DrawingAreaProxy.cpp
 UIProcess/FrameLoadState.cpp
 UIProcess/GeolocationPermissionRequestManagerProxy.cpp
 UIProcess/GeolocationPermissionRequestProxy.cpp
+UIProcess/InspectorBrowserAgent.cpp
+UIProcess/InspectorDialogAgent.cpp
 UIProcess/LegacyGlobalSettings.cpp
 UIProcess/PageLoadState.cpp
 UIProcess/ProcessAssertion.cpp
 UIProcess/ProcessThrottler.cpp
 UIProcess/ProvisionalPageProxy.cpp
+UIProcess/RemoteInspectorPipe.cpp
 UIProcess/ResponsivenessTimer.cpp
 UIProcess/StatisticsRequest.cpp
 UIProcess/SuspendedPageProxy.cpp
@@ -309,6 +314,8 @@ UIProcess/WebOpenPanelResultListenerProxy.cpp
 UIProcess/WebPageDiagnosticLoggingClient.cpp
 UIProcess/WebPageGroup.cpp
 UIProcess/WebPageInjectedBundleClient.cpp
+UIProcess/WebPageInspectorEmulationAgent.cpp
+UIProcess/WebPageInspectorInputAgent.cpp
 UIProcess/WebPageProxy.cpp
 UIProcess/WebPasteboardProxy.cpp
 UIProcess/WebPreferences.cpp
diff --git a/Source/WebKit/SourcesCocoa.txt b/Source/WebKit/SourcesCocoa.txt
index da23b0e5d30cc5469ee4d709e1fa8ad13dc80601..ae54ff36c159cbe9dfc015092b426651f3d0091c 100644
--- a/Source/WebKit/SourcesCocoa.txt
+++ b/Source/WebKit/SourcesCocoa.txt
@@ -248,6 +248,7 @@ UIProcess/API/Cocoa/_WKApplicationManifest.mm
 UIProcess/API/Cocoa/_WKAttachment.mm
 UIProcess/API/Cocoa/_WKAutomationSession.mm
 UIProcess/API/Cocoa/_WKAutomationSessionConfiguration.mm
+UIProcess/API/Cocoa/_WKBrowserInspector.mm
 UIProcess/API/Cocoa/_WKContentRuleListAction.mm
 UIProcess/API/Cocoa/_WKContextMenuElementInfo.mm
 UIProcess/API/Cocoa/_WKCustomHeaderFields.mm @no-unify
diff --git a/Source/WebKit/SourcesGTK.txt b/Source/WebKit/SourcesGTK.txt
index eba34614fe0fdcee53c1edc4e940c41bbd24027c..dda27075fa5bbbbd0116b2956a7fbe03542bd588 100644
--- a/Source/WebKit/SourcesGTK.txt
+++ b/Source/WebKit/SourcesGTK.txt
@@ -130,6 +130,7 @@ UIProcess/API/glib/WebKitAuthenticationRequest.cpp @no-unify
 UIProcess/API/glib/WebKitAutomationSession.cpp @no-unify
 UIProcess/API/glib/WebKitBackForwardList.cpp @no-unify
 UIProcess/API/glib/WebKitBackForwardListItem.cpp @no-unify
+UIProcess/API/glib/WebKitBrowserInspector.cpp @no-unify
 UIProcess/API/glib/WebKitContextMenuClient.cpp @no-unify
 UIProcess/API/glib/WebKitCookieManager.cpp @no-unify
 UIProcess/API/glib/WebKitCredential.cpp @no-unify
@@ -237,6 +238,7 @@ UIProcess/WebsiteData/unix/WebsiteDataStoreUnix.cpp
 
 UIProcess/cairo/BackingStoreCairo.cpp @no-unify
 
+UIProcess/glib/InspectorBrowserAgentClientGLib.cpp
 UIProcess/glib/WebProcessPoolGLib.cpp
 UIProcess/glib/WebProcessProxyGLib.cpp
 UIProcess/glib/WebsiteDataStoreGLib.cpp @no-unify
@@ -250,6 +252,7 @@ UIProcess/gtk/AcceleratedBackingStoreX11.cpp @no-unify
 UIProcess/gtk/DragAndDropHandler.cpp
 UIProcess/gtk/GestureController.cpp
 UIProcess/gtk/HardwareAccelerationManager.cpp
+UIProcess/gtk/InspectorTargetProxyGtk.cpp
 UIProcess/gtk/KeyBindingTranslator.cpp
 UIProcess/gtk/PointerLockManager.cpp @no-unify
 UIProcess/gtk/PointerLockManagerWayland.cpp @no-unify
@@ -261,6 +264,8 @@ UIProcess/gtk/WaylandCompositor.cpp @no-unify
 UIProcess/gtk/WebColorPickerGtk.cpp
 UIProcess/gtk/WebContextMenuProxyGtk.cpp
 UIProcess/gtk/WebDataListSuggestionsDropdownGtk.cpp
+UIProcess/gtk/WebPageInspectorEmulationAgentGtk.cpp
+UIProcess/gtk/WebPageInspectorInputAgentGtk.cpp
 UIProcess/gtk/WebPageProxyGtk.cpp @no-unify
 UIProcess/gtk/WebPasteboardProxyGtk.cpp
 UIProcess/gtk/WebPopupMenuProxyGtk.cpp
diff --git a/Source/WebKit/SourcesWPE.txt b/Source/WebKit/SourcesWPE.txt
index 69a52e17a4a8932b5dfc5edfa72b922c18d43082..f859e07168077d10918f954cca699c4e1729cd44 100644
--- a/Source/WebKit/SourcesWPE.txt
+++ b/Source/WebKit/SourcesWPE.txt
@@ -118,6 +118,7 @@ UIProcess/API/glib/WebKitAuthenticationRequest.cpp @no-unify
 UIProcess/API/glib/WebKitAutomationSession.cpp @no-unify
 UIProcess/API/glib/WebKitBackForwardList.cpp @no-unify
 UIProcess/API/glib/WebKitBackForwardListItem.cpp @no-unify
+UIProcess/API/glib/WebKitBrowserInspector.cpp @no-unify
 UIProcess/API/glib/WebKitContextMenuClient.cpp @no-unify
 UIProcess/API/glib/WebKitCookieManager.cpp @no-unify
 UIProcess/API/glib/WebKitCredential.cpp @no-unify
@@ -193,7 +194,7 @@ UIProcess/Automation/wpe/WebAutomationSessionWPE.cpp
 UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.cpp
 
 UIProcess/geoclue/GeoclueGeolocationProvider.cpp
-
+UIProcess/glib/InspectorBrowserAgentClientGLib.cpp
 UIProcess/glib/WebProcessPoolGLib.cpp
 UIProcess/glib/WebProcessProxyGLib.cpp
 UIProcess/glib/WebsiteDataStoreGLib.cpp @no-unify
@@ -220,6 +221,10 @@ UIProcess/soup/WebProcessPoolSoup.cpp
 
 UIProcess/wpe/WebPageProxyWPE.cpp
 
+UIProcess/wpe/InspectorTargetProxyWPE.cpp
+UIProcess/wpe/WebPageInspectorEmulationAgentWPE.cpp
+UIProcess/wpe/WebPageInspectorInputAgentWPE.cpp
+
 WebProcess/InjectedBundle/API/glib/DOM/DOMObjectCache.cpp @no-unify
 WebProcess/InjectedBundle/API/glib/DOM/WebKitDOMDocument.cpp @no-unify
 WebProcess/InjectedBundle/API/glib/DOM/WebKitDOMElement.cpp @no-unify
diff --git a/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.cpp b/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.cpp
index c392bc9ba6a0dc331981e03e300c6e31ebd75565..689bff826fb6ac76b7de65652ea40b0eb7525f85 100644
--- a/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.cpp
+++ b/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.cpp
@@ -53,6 +53,9 @@ Ref<ProcessPoolConfiguration> ProcessPoolConfiguration::copy()
     copy->m_ignoreSynchronousMessagingTimeoutsForTesting = this->m_ignoreSynchronousMessagingTimeoutsForTesting;
     copy->m_attrStyleEnabled = this->m_attrStyleEnabled;
     copy->m_overrideLanguages = this->m_overrideLanguages;
+#if PLATFORM(MAC)
+    copy->m_forceOverlayScrollbars = this->m_forceOverlayScrollbars;
+#endif
     copy->m_alwaysRunsAtBackgroundPriority = this->m_alwaysRunsAtBackgroundPriority;
     copy->m_shouldTakeUIBackgroundAssertion = this->m_shouldTakeUIBackgroundAssertion;
     copy->m_shouldCaptureAudioInUIProcess = this->m_shouldCaptureAudioInUIProcess;
diff --git a/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.h b/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.h
index 8a0ca8e4de1e35423e06614728afbe07e474db81..7f01a8ce5a9ca8bfbdf715759292e663a6ac85d8 100644
--- a/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.h
+++ b/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.h
@@ -98,6 +98,11 @@ public:
     const Vector<WTF::String>& overrideLanguages() const { return m_overrideLanguages; }
     void setOverrideLanguages(Vector<WTF::String>&& languages) { m_overrideLanguages = WTFMove(languages); }
     
+#if PLATFORM(MAC)
+    bool forceOverlayScrollbars() const { return m_forceOverlayScrollbars; }
+    void setForceOverlayScrollbars(bool forceOverlayScrollbars) { m_forceOverlayScrollbars = forceOverlayScrollbars; }
+#endif
+
     bool alwaysRunsAtBackgroundPriority() const { return m_alwaysRunsAtBackgroundPriority; }
     void setAlwaysRunsAtBackgroundPriority(bool alwaysRunsAtBackgroundPriority) { m_alwaysRunsAtBackgroundPriority = alwaysRunsAtBackgroundPriority; }
 
@@ -153,6 +158,9 @@ private:
     bool m_ignoreSynchronousMessagingTimeoutsForTesting { false };
     bool m_attrStyleEnabled { false };
     Vector<WTF::String> m_overrideLanguages;
+#if PLATFORM(MAC)
+    bool m_forceOverlayScrollbars { false };
+#endif
     bool m_alwaysRunsAtBackgroundPriority { false };
     bool m_shouldTakeUIBackgroundAssertion { true };
     bool m_shouldCaptureAudioInUIProcess { false };
diff --git a/Source/WebKit/UIProcess/API/APIUIClient.h b/Source/WebKit/UIProcess/API/APIUIClient.h
index 54513035b261bfd5e187ec945796198ed09d88b1..2d3200e4f6e90a16f248b255f75d2a7e17d895a5 100644
--- a/Source/WebKit/UIProcess/API/APIUIClient.h
+++ b/Source/WebKit/UIProcess/API/APIUIClient.h
@@ -97,6 +97,7 @@ public:
     virtual void runJavaScriptAlert(WebKit::WebPageProxy&, const WTF::String&, WebKit::WebFrameProxy*, WebCore::SecurityOriginData&&, Function<void()>&& completionHandler) { completionHandler(); }
     virtual void runJavaScriptConfirm(WebKit::WebPageProxy&, const WTF::String&, WebKit::WebFrameProxy*, WebCore::SecurityOriginData&&, Function<void(bool)>&& completionHandler) { completionHandler(false); }
     virtual void runJavaScriptPrompt(WebKit::WebPageProxy&, const WTF::String&, const WTF::String&, WebKit::WebFrameProxy*, WebCore::SecurityOriginData&&, Function<void(const WTF::String&)>&& completionHandler) { completionHandler(WTF::String()); }
+    virtual void handleJavaScriptDialog(WebKit::WebPageProxy&, bool, const WTF::String&) { }
 
     virtual void setStatusText(WebKit::WebPageProxy*, const WTF::String&) { }
     virtual void mouseDidMoveOverElement(WebKit::WebPageProxy&, const WebKit::WebHitTestResultData&, OptionSet<WebKit::WebEvent::Modifier>, Object*) { }
diff --git a/Source/WebKit/UIProcess/API/C/WKContext.cpp b/Source/WebKit/UIProcess/API/C/WKContext.cpp
index 743cb854e28f51a0399d6fd1589e767fa3494f25..a6667051636cef88fb9dacc928cde16ba5215266 100644
--- a/Source/WebKit/UIProcess/API/C/WKContext.cpp
+++ b/Source/WebKit/UIProcess/API/C/WKContext.cpp
@@ -436,6 +436,11 @@ WKWebsiteDataStoreRef WKContextGetWebsiteDataStore(WKContextRef)
     return WKWebsiteDataStoreGetDefaultDataStore();
 }
 
+void WKContextSetPrimaryDataStore(WKContextRef contextRef, WKWebsiteDataStoreRef dataStoreRef)
+{
+    WebKit::toImpl(contextRef)->setPrimaryDataStore(*WebKit::toImpl(dataStoreRef));
+}
+
 WKApplicationCacheManagerRef WKContextGetApplicationCacheManager(WKContextRef context)
 {
     return reinterpret_cast<WKApplicationCacheManagerRef>(WKWebsiteDataStoreGetDefaultDataStore());
diff --git a/Source/WebKit/UIProcess/API/C/WKContext.h b/Source/WebKit/UIProcess/API/C/WKContext.h
index 08f54ff5057f8d04e26adfe2c0e3a472647935e7..8f3ae0f0346514cec926ea7babff40c22fd4097a 100644
--- a/Source/WebKit/UIProcess/API/C/WKContext.h
+++ b/Source/WebKit/UIProcess/API/C/WKContext.h
@@ -168,6 +168,7 @@ WK_EXPORT void WKContextStartMemorySampler(WKContextRef context, WKDoubleRef int
 WK_EXPORT void WKContextStopMemorySampler(WKContextRef context);
 
 WK_EXPORT WKWebsiteDataStoreRef WKContextGetWebsiteDataStore(WKContextRef context) WK_C_API_DEPRECATED_WITH_REPLACEMENT(WKWebsiteDataStoreGetDefaultDataStore);
+WK_EXPORT void WKContextSetPrimaryDataStore(WKContextRef context, WKWebsiteDataStoreRef dataStore);
 
 WK_EXPORT WKApplicationCacheManagerRef WKContextGetApplicationCacheManager(WKContextRef context) WK_C_API_DEPRECATED_WITH_REPLACEMENT(WKWebsiteDataStoreGetDefaultDataStore);
 WK_EXPORT WKCookieManagerRef WKContextGetCookieManager(WKContextRef context) WK_C_API_DEPRECATED;
diff --git a/Source/WebKit/UIProcess/API/C/WKInspector.cpp b/Source/WebKit/UIProcess/API/C/WKInspector.cpp
index 39327c5c9230591e4f52e4574c416e36687788f0..c84fe4e5249cfec5d65805868769c99200eb27da 100644
--- a/Source/WebKit/UIProcess/API/C/WKInspector.cpp
+++ b/Source/WebKit/UIProcess/API/C/WKInspector.cpp
@@ -28,6 +28,11 @@
 
 #if !PLATFORM(IOS_FAMILY)
 
+#if PLATFORM(WIN)
+#include "BrowserInspectorPipe.h"
+#include "InspectorBrowserAgentClientWin.h"
+#endif
+
 #include "WKAPICast.h"
 #include "WebInspectorProxy.h"
 #include "WebPageProxy.h"
@@ -130,4 +135,11 @@ void WKInspectorToggleElementSelection(WKInspectorRef inspectorRef)
     toImpl(inspectorRef)->toggleElementSelection();
 }
 
+void WKInspectorInitializeRemoteInspectorPipe(CreatePageCallback createPage, QuitCallback quit)
+{
+#if PLATFORM(WIN)
+    initializeBrowserInspectorPipe(makeUnique<InspectorBrowserAgentClientWin>(createPage, quit));
+#endif
+}
+
 #endif // !PLATFORM(IOS_FAMILY)
diff --git a/Source/WebKit/UIProcess/API/C/WKInspector.h b/Source/WebKit/UIProcess/API/C/WKInspector.h
index 026121d114c5fcad84c1396be8d692625beaa3bd..1f707641766b51e3bddcdde0c49ee8cfcd83db0b 100644
--- a/Source/WebKit/UIProcess/API/C/WKInspector.h
+++ b/Source/WebKit/UIProcess/API/C/WKInspector.h
@@ -66,6 +66,9 @@ WK_EXPORT void WKInspectorTogglePageProfiling(WKInspectorRef inspector);
 WK_EXPORT bool WKInspectorIsElementSelectionActive(WKInspectorRef inspector);
 WK_EXPORT void WKInspectorToggleElementSelection(WKInspectorRef inspector);
 
+typedef WKPageRef (*CreatePageCallback)(WKPageConfigurationRef configuration);
+typedef void (*QuitCallback)();
+WK_EXPORT void WKInspectorInitializeRemoteInspectorPipe(CreatePageCallback, QuitCallback);
 #ifdef __cplusplus
 }
 #endif
diff --git a/Source/WebKit/UIProcess/API/C/WKPage.cpp b/Source/WebKit/UIProcess/API/C/WKPage.cpp
index d7279554675b31a64e5edc1f6f3c83db17929856..8a9b018ae491d7538566ed2771fac46b6d325f57 100644
--- a/Source/WebKit/UIProcess/API/C/WKPage.cpp
+++ b/Source/WebKit/UIProcess/API/C/WKPage.cpp
@@ -1676,6 +1676,13 @@ void WKPageSetPageUIClient(WKPageRef pageRef, const WKPageUIClientBase* wkClient
             completionHandler(String());
         }
 
+        void handleJavaScriptDialog(WebPageProxy& page, bool accept, const String& value) final {
+            if (m_client.handleJavaScriptDialog) {
+                m_client.handleJavaScriptDialog(toAPI(&page), accept, toAPI(value.impl()), m_client.base.clientInfo);
+                return;
+            }
+        }
+
         void setStatusText(WebPageProxy* page, const String& text) final
         {
             if (!m_client.setStatusText)
@@ -1736,6 +1743,8 @@ void WKPageSetPageUIClient(WKPageRef pageRef, const WKPageUIClientBase* wkClient
         {
             if (!m_client.didNotHandleKeyEvent)
                 return;
+            if (!event.nativeEvent())
+                return;
             m_client.didNotHandleKeyEvent(toAPI(page), event.nativeEvent(), m_client.base.clientInfo);
         }
 
diff --git a/Source/WebKit/UIProcess/API/C/WKPageUIClient.h b/Source/WebKit/UIProcess/API/C/WKPageUIClient.h
index 1d2febfba8833912f72216aa53c8c20090ee2d8b..1b2c3d84b15b12f1a187c0b7622db43cbbcd5996 100644
--- a/Source/WebKit/UIProcess/API/C/WKPageUIClient.h
+++ b/Source/WebKit/UIProcess/API/C/WKPageUIClient.h
@@ -90,6 +90,7 @@ typedef void (*WKPageRunBeforeUnloadConfirmPanelCallback)(WKPageRef page, WKStri
 typedef void (*WKPageRunJavaScriptAlertCallback)(WKPageRef page, WKStringRef alertText, WKFrameRef frame, WKSecurityOriginRef securityOrigin, WKPageRunJavaScriptAlertResultListenerRef listener, const void *clientInfo);
 typedef void (*WKPageRunJavaScriptConfirmCallback)(WKPageRef page, WKStringRef message, WKFrameRef frame, WKSecurityOriginRef securityOrigin, WKPageRunJavaScriptConfirmResultListenerRef listener, const void *clientInfo);
 typedef void (*WKPageRunJavaScriptPromptCallback)(WKPageRef page, WKStringRef message, WKStringRef defaultValue, WKFrameRef frame, WKSecurityOriginRef securityOrigin, WKPageRunJavaScriptPromptResultListenerRef listener, const void *clientInfo);
+typedef void (*WKPageHandleJavaScriptDialogCallback)(WKPageRef page, bool accept, WKStringRef value, const void *clientInfo);
 typedef void (*WKPageRequestStorageAccessConfirmCallback)(WKPageRef page, WKFrameRef frame, WKStringRef requestingDomain, WKStringRef currentDomain, WKPageRequestStorageAccessConfirmResultListenerRef listener, const void *clientInfo);
 typedef void (*WKPageTakeFocusCallback)(WKPageRef page, WKFocusDirection direction, const void *clientInfo);
 typedef void (*WKPageFocusCallback)(WKPageRef page, const void *clientInfo);
@@ -1352,6 +1353,7 @@ typedef struct WKPageUIClientV14 {
 
     // Version 14.
     WKPageRunWebAuthenticationPanelCallback                             runWebAuthenticationPanel;
+    WKPageHandleJavaScriptDialogCallback                                handleJavaScriptDialog;
 } WKPageUIClientV14;
 
 #ifdef __cplusplus
diff --git a/Source/WebKit/UIProcess/API/Cocoa/WKProcessPool.mm b/Source/WebKit/UIProcess/API/Cocoa/WKProcessPool.mm
index 032584571cb63dbe6b49a7953f6e8d6d7e83e375..766b1e0456a490eb60eeef01c8edd8577ab3fe1a 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/WKProcessPool.mm
+++ b/Source/WebKit/UIProcess/API/Cocoa/WKProcessPool.mm
@@ -47,6 +47,7 @@
 #import "_WKDownloadDelegate.h"
 #import "_WKDownloadInternal.h"
 #import "_WKProcessPoolConfigurationInternal.h"
+#import "_WKWebsiteDataStoreInternal.h"
 #import <WebCore/CertificateInfo.h>
 #import <WebCore/HTTPCookieAcceptPolicyCocoa.h>
 #import <WebCore/PluginData.h>
@@ -84,6 +85,18 @@ static WKProcessPool *sharedProcessPool;
     return self;
 }
 
+- (instancetype)_initWithConfiguration:(_WKProcessPoolConfiguration *)configuration AndDataStore:(WKWebsiteDataStore*)dataStore
+{
+    if (!(self = [super init]))
+        return nil;
+
+    API::Object::constructInWrapper<WebKit::WebProcessPool>(self, *configuration->_processPoolConfiguration);
+    _processPool->setPrimaryDataStore(*dataStore->_websiteDataStore);
+
+    return self;
+}
+
+
 - (instancetype)init
 {
     return [self _initWithConfiguration:adoptNS([[_WKProcessPoolConfiguration alloc] init]).get()];
diff --git a/Source/WebKit/UIProcess/API/Cocoa/WKProcessPoolPrivate.h b/Source/WebKit/UIProcess/API/Cocoa/WKProcessPoolPrivate.h
index cc0f99cf9b1fb80dfd023c2200c66d87d494d6c4..96713376932923a342d0c973216c96925d18dbf0 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/WKProcessPoolPrivate.h
+++ b/Source/WebKit/UIProcess/API/Cocoa/WKProcessPoolPrivate.h
@@ -37,6 +37,7 @@
 
 @interface WKProcessPool ()
 - (instancetype)_initWithConfiguration:(_WKProcessPoolConfiguration *)configuration __attribute__((objc_method_family(init))) NS_DESIGNATED_INITIALIZER;
+- (instancetype)_initWithConfiguration:(_WKProcessPoolConfiguration *)configuration AndDataStore:(WKWebsiteDataStore *)dataStore __attribute__((objc_method_family(init))) NS_DESIGNATED_INITIALIZER;
 @end
 
 @interface WKProcessPool (WKPrivate)
diff --git a/Source/WebKit/UIProcess/API/Cocoa/WKUIDelegate.h b/Source/WebKit/UIProcess/API/Cocoa/WKUIDelegate.h
index cad87f3ef2ab93d93a74cec0c34b47c695de6bc6..66145a384638b97ee08516e56e1e86a83713c634 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/WKUIDelegate.h
+++ b/Source/WebKit/UIProcess/API/Cocoa/WKUIDelegate.h
@@ -123,6 +123,13 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(nullable NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * _Nullable result))completionHandler;
 
+/*! @abstract Handle a JavaScript dialog.
+ @param webView The web view invoking the delegate method.
+ @param accept Whether to accept the dialog.
+ @param value Value to use for prompt dialog.
+ */
+- (void)webView:(WKWebView *)webView handleJavaScriptDialog:(BOOL)accept value:(nullable NSString *)value;
+
 #if TARGET_OS_IPHONE
 
 /*! @abstract Allows your app to determine whether or not the given element should show a preview.
diff --git a/Source/WebKit/UIProcess/API/Cocoa/WKWebsiteDataStore.h b/Source/WebKit/UIProcess/API/Cocoa/WKWebsiteDataStore.h
index 726c4972aa0b32e0dc602e0ab2d71f6ae8ef93ae..c67f408797724cb6d68ed441c0ef1cccd33ca1e0 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/WKWebsiteDataStore.h
+++ b/Source/WebKit/UIProcess/API/Cocoa/WKWebsiteDataStore.h
@@ -24,7 +24,6 @@
  */
 
 #import <WebKit/WKFoundation.h>
-
 #import <WebKit/WKWebsiteDataRecord.h>
 
 NS_ASSUME_NONNULL_BEGIN
@@ -78,6 +77,8 @@ WK_CLASS_AVAILABLE(macos(10.11), ios(9.0))
 /*! @abstract Returns the cookie store representing HTTP cookies in this website data store. */
 @property (nonatomic, readonly) WKHTTPCookieStore *httpCookieStore WK_API_AVAILABLE(macos(10.13), ios(11.0));
 
+- (uint64_t)sessionID;
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/Source/WebKit/UIProcess/API/Cocoa/WKWebsiteDataStore.mm b/Source/WebKit/UIProcess/API/Cocoa/WKWebsiteDataStore.mm
index 179cd971a23fe25a4a363ddd72cd2da050e28c8a..0d72efbe5106b2d8d11b91f1f394739d9a3d25c4 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/WKWebsiteDataStore.mm
+++ b/Source/WebKit/UIProcess/API/Cocoa/WKWebsiteDataStore.mm
@@ -44,6 +44,7 @@
 #import "_WKWebsiteDataStoreDelegate.h"
 #import <WebCore/Credential.h>
 #import <WebCore/RegistrationDatabase.h>
+#import <pal/SessionID.h>
 #import <wtf/BlockPtr.h>
 #import <wtf/URL.h>
 #import <wtf/WeakObjCPtr.h>
@@ -184,6 +185,11 @@ static WallTime toSystemClockTime(NSDate *date)
     });
 }
 
+- (uint64_t) sessionID
+{
+    return _websiteDataStore->sessionID().toUInt64();
+}
+
 static Vector<WebKit::WebsiteDataRecord> toWebsiteDataRecords(NSArray *dataRecords)
 {
     Vector<WebKit::WebsiteDataRecord> result;
diff --git a/Source/WebKit/UIProcess/API/Cocoa/_WKBrowserInspector.h b/Source/WebKit/UIProcess/API/Cocoa/_WKBrowserInspector.h
new file mode 100644
index 0000000000000000000000000000000000000000..b64d1a6d54ec15a99164294706543cee626d1050
--- /dev/null
+++ b/Source/WebKit/UIProcess/API/Cocoa/_WKBrowserInspector.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import <WebKit/WKFoundation.h>
+#import <WebKit/WKProcessPool.h>
+#import <WebKit/WKWebsiteDataStore.h>
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@class WKWebView;
+
+WK_CLASS_AVAILABLE(macos(10.14.0))
+@interface _WKBrowserContext : NSObject
+@property (nonatomic, strong) WKWebsiteDataStore *dataStore;
+@property (nonatomic, strong) WKProcessPool *processPool;
+@end
+
+@protocol _WKBrowserInspectorDelegate <NSObject>
+- (WKWebView *)createNewPage:(uint64_t)sessionID;
+- (_WKBrowserContext *)createBrowserContext;
+- (void)deleteBrowserContext:(uint64_t)sessionID;
+- (void)quit;
+@end
+
+WK_CLASS_AVAILABLE(macos(10.14.0))
+@interface _WKBrowserInspector : NSObject
++ (void)initializeRemoteInspectorPipe:(id<_WKBrowserInspectorDelegate>)delegate headless:(BOOL)headless;
+@end
+
+
+NS_ASSUME_NONNULL_END
+
diff --git a/Source/WebKit/UIProcess/API/Cocoa/_WKBrowserInspector.mm b/Source/WebKit/UIProcess/API/Cocoa/_WKBrowserInspector.mm
new file mode 100644
index 0000000000000000000000000000000000000000..41604f05e700d40638469c226b54d44ee748bd22
--- /dev/null
+++ b/Source/WebKit/UIProcess/API/Cocoa/_WKBrowserInspector.mm
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "_WKBrowserInspector.h"
+
+#include "BrowserInspectorPipe.h"
+#include "InspectorBrowserAgentClientMac.h"
+#include "PageClientImplMac.h"
+#include "WebKit2Initialize.h"
+
+#import "WKWebView.h"
+
+using namespace WebKit;
+
+@implementation _WKBrowserInspector
+
++ (void)initializeRemoteInspectorPipe:(id<_WKBrowserInspectorDelegate>)delegate headless:(BOOL)headless
+{
+#if ENABLE(REMOTE_INSPECTOR)
+    InitializeWebKit2();
+    PageClientImpl::setHeadless(headless);
+    initializeBrowserInspectorPipe(makeUnique<InspectorBrowserAgentClientMac>(delegate));
+#endif
+}
+
+@end
+
+@implementation _WKBrowserContext
+- (void)dealloc
+{
+    [_dataStore release];
+    [_processPool release];
+    _dataStore = nil;
+    _processPool = nil;
+    [super dealloc];
+}
+@end
diff --git a/Source/WebKit/UIProcess/API/Cocoa/_WKProcessPoolConfiguration.h b/Source/WebKit/UIProcess/API/Cocoa/_WKProcessPoolConfiguration.h
index 04922b10809ed4754279184a42169defa5f01ec8..a40edf790cded9f05943aa226db1e1e7e7211cb6 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/_WKProcessPoolConfiguration.h
+++ b/Source/WebKit/UIProcess/API/Cocoa/_WKProcessPoolConfiguration.h
@@ -62,6 +62,7 @@ WK_CLASS_AVAILABLE(macos(10.10), ios(8.0))
 #endif
 @property (nonatomic) pid_t presentingApplicationPID WK_API_AVAILABLE(macos(10.13), ios(11.0));
 @property (nonatomic) BOOL processSwapsOnNavigation WK_API_AVAILABLE(macos(10.14), ios(12.0));
+@property (nonatomic) BOOL forceOverlayScrollbars WK_API_AVAILABLE(macos(10.14));
 @property (nonatomic) BOOL alwaysKeepAndReuseSwappedProcesses WK_API_AVAILABLE(macos(10.14), ios(12.0));
 @property (nonatomic) BOOL processSwapsOnWindowOpenWithOpener WK_API_AVAILABLE(macos(10.14), ios(12.0));
 @property (nonatomic) BOOL prewarmsProcessesAutomatically WK_API_AVAILABLE(macos(10.14.4), ios(12.2));
diff --git a/Source/WebKit/UIProcess/API/Cocoa/_WKProcessPoolConfiguration.mm b/Source/WebKit/UIProcess/API/Cocoa/_WKProcessPoolConfiguration.mm
index 0e44b5a524486a7df2473f399ab4829fdfa3f2b7..a5149fcf79dde9c159bb793eacc19a77bd196858 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/_WKProcessPoolConfiguration.mm
+++ b/Source/WebKit/UIProcess/API/Cocoa/_WKProcessPoolConfiguration.mm
@@ -271,6 +271,16 @@
     return _processPoolConfiguration->processSwapsOnNavigation();
 }
 
+- (void)setForceOverlayScrollbars:(BOOL)force
+{
+    _processPoolConfiguration->setForceOverlayScrollbars(force);
+}
+
+- (BOOL)forceOverlayScrollbars
+{
+    return _processPoolConfiguration->forceOverlayScrollbars();
+}
+
 - (void)setPrewarmsProcessesAutomatically:(BOOL)prewarms
 {
     _processPoolConfiguration->setIsAutomaticProcessWarmingEnabled(prewarms);
diff --git a/Source/WebKit/UIProcess/API/Cocoa/_WKRemoteWebInspectorViewController.mm b/Source/WebKit/UIProcess/API/Cocoa/_WKRemoteWebInspectorViewController.mm
index 2bdb8b9e7256f22096ebaa5d51959aa52389ca0a..2141d9d17497861a6c711f99306de10992a93ce8 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/_WKRemoteWebInspectorViewController.mm
+++ b/Source/WebKit/UIProcess/API/Cocoa/_WKRemoteWebInspectorViewController.mm
@@ -25,6 +25,7 @@
 
 #import "config.h"
 #import "_WKRemoteWebInspectorViewController.h"
+#import "WKWebViewPrivate.h"
 
 #if PLATFORM(MAC)
 
diff --git a/Source/WebKit/UIProcess/API/glib/WebKitBrowserInspector.cpp b/Source/WebKit/UIProcess/API/glib/WebKitBrowserInspector.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..70081db72e035ca99c0279ab02da5cfed9256c57
--- /dev/null
+++ b/Source/WebKit/UIProcess/API/glib/WebKitBrowserInspector.cpp
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "WebKitBrowserInspector.h"
+
+#include "BrowserInspectorPipe.h"
+#include "InspectorBrowserAgentClientGLib.h"
+#include "WebKitBrowserInspectorPrivate.h"
+#include "WebKitWebViewPrivate.h"
+#include <wtf/glib/GRefPtr.h>
+#include <wtf/glib/WTFGType.h>
+
+/**
+ * SECTION: WebKitBrowserInspector
+ * @Short_description: Access to the WebKit browser inspector
+ * @Title: WebKitBrowserInspector
+ *
+ * The WebKit Browser Inspector is an experimental API that provides
+ * access to the inspector via the remote debugging protocol. The protocol
+ * allows to create ephemeral contexts and create pages in them and then
+ * manipulate them using the inspector commands. This may be useful for
+ * the browser automation or remote debugging.
+ *
+ * Currently the protocol can be exposed to the parent process via a unix
+ * pipe.
+ */
+
+enum {
+    CREATE_NEW_PAGE,
+
+    LAST_SIGNAL
+};
+
+struct _WebKitBrowserInspectorPrivate {
+    int unused { 0 };
+};
+
+WEBKIT_DEFINE_TYPE(WebKitBrowserInspector, webkit_browser_inspector, G_TYPE_OBJECT)
+
+static guint signals[LAST_SIGNAL] = { 0, };
+
+static void webkit_browser_inspector_class_init(WebKitBrowserInspectorClass* findClass)
+{
+    GObjectClass* gObjectClass = G_OBJECT_CLASS(findClass);
+
+    /**
+     * WebKitBrowserInspector::create-new-page:
+     * @inspector: the #WebKitBrowserInspector on which the signal is emitted
+     *
+     * Emitted when the inspector is requested to create a new page in the provided
+     * #WebKitWebContext.
+     *
+     * This signal is emitted when inspector receives 'Browser.createPage' command
+     * from its remote client. If the signla is not handled the command will fail.
+     *
+     * Returns: %WebKitWebView that contains created page.
+     */
+    signals[CREATE_NEW_PAGE] = g_signal_new(
+        "create-new-page",
+        G_TYPE_FROM_CLASS(gObjectClass),
+        G_SIGNAL_RUN_LAST,
+        G_STRUCT_OFFSET(WebKitBrowserInspectorClass, create_new_page),
+        nullptr, nullptr,
+        g_cclosure_marshal_generic,
+#if PLATFORM(GTK)
+        GTK_TYPE_WIDGET,
+#else
+        WEBKIT_TYPE_WEB_VIEW,
+#endif
+        1,
+        WEBKIT_TYPE_WEB_CONTEXT);
+}
+
+WebKit::WebPageProxy* webkitBrowserInspectorCreateNewPageInContext(WebKitWebContext* context)
+{
+    WebKitWebView* newWebView;
+    g_signal_emit(webkit_browser_inspector_get_default(), signals[CREATE_NEW_PAGE], 0, context, &newWebView);
+    if (!newWebView)
+        return nullptr;
+    return  &webkitWebViewGetPage(newWebView);
+}
+
+static gpointer createWebKitBrowserInspector(gpointer)
+{
+    static GRefPtr<WebKitBrowserInspector> browserInspector = adoptGRef(WEBKIT_BROWSER_INSPECTOR(g_object_new(WEBKIT_TYPE_BROWSER_INSPECTOR, nullptr)));
+    return browserInspector.get();
+}
+
+/**
+ * webkit_browser_inspector_get_default:
+ *
+ * Gets the default instance of the browser inspector.
+ *
+ * Returns: (transfer none): a #WebKitBrowserInspector
+ */
+WebKitBrowserInspector* webkit_browser_inspector_get_default(void)
+{
+    static GOnce onceInit = G_ONCE_INIT;
+    return WEBKIT_BROWSER_INSPECTOR(g_once(&onceInit, createWebKitBrowserInspector, 0));
+}
+
+/**
+ * webkit_browser_inspector_initialize_pipe:
+ *
+ * Creates browser inspector and configures pipe handler to communicate with
+ * the parent process.
+ */
+void webkit_browser_inspector_initialize_pipe(GMainLoop* mainLoop)
+{
+#if ENABLE(REMOTE_INSPECTOR)
+    WebKit::initializeBrowserInspectorPipe(makeUnique<WebKit::InspectorBrowserAgentClientGlib>(mainLoop));
+#endif
+}
diff --git a/Source/WebKit/UIProcess/API/glib/WebKitBrowserInspectorPrivate.h b/Source/WebKit/UIProcess/API/glib/WebKitBrowserInspectorPrivate.h
new file mode 100644
index 0000000000000000000000000000000000000000..1bff4e694f19264d1be418198b7921780e4f8309
--- /dev/null
+++ b/Source/WebKit/UIProcess/API/glib/WebKitBrowserInspectorPrivate.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "WebKitBrowserInspector.h"
+#include "WebPageProxy.h"
+
+WebKit::WebPageProxy* webkitBrowserInspectorCreateNewPageInContext(WebKitWebContext*);
diff --git a/Source/WebKit/UIProcess/API/glib/WebKitUIClient.cpp b/Source/WebKit/UIProcess/API/glib/WebKitUIClient.cpp
index f769407fdc660c6f6fef77af90a43bd5dca9d544..bee8a907fb9a7924d9551d9aa64d98fb8c5746de 100644
--- a/Source/WebKit/UIProcess/API/glib/WebKitUIClient.cpp
+++ b/Source/WebKit/UIProcess/API/glib/WebKitUIClient.cpp
@@ -64,7 +64,8 @@ private:
     void createNewPage(WebPageProxy& page, WebCore::WindowFeatures&& windowFeatures, Ref<API::NavigationAction>&& apiNavigationAction, CompletionHandler<void(RefPtr<WebPageProxy>&&)>&& completionHandler) final
     {
         WebKitNavigationAction navigationAction(WTFMove(apiNavigationAction));
-        completionHandler(webkitWebViewCreateNewPage(m_webView, windowFeatures, &navigationAction));
+        WebPageProxy* newPage = webkitWebViewCreateNewPage(m_webView, windowFeatures, &navigationAction);
+        completionHandler(adoptRef(newPage));
     }
 
     void showPage(WebPageProxy*) final
@@ -91,6 +92,10 @@ private:
     {
         webkitWebViewRunJavaScriptPrompt(m_webView, message.utf8(), defaultValue.utf8(), WTFMove(completionHandler));
     }
+    void handleJavaScriptDialog(WebPageProxy&, bool accept, const String& value) final
+    {
+        webkitWebViewHandleJavaScriptDialog(m_webView, accept, value);
+    }
 
     bool canRunBeforeUnloadConfirmPanel() const final { return true; }
 
diff --git a/Source/WebKit/UIProcess/API/glib/WebKitWebContext.cpp b/Source/WebKit/UIProcess/API/glib/WebKitWebContext.cpp
index 33a9b7d5ad060f275dcf7156a8cff3f37644e736..128a5c75807848de10aed628618fc7d149a42792 100644
--- a/Source/WebKit/UIProcess/API/glib/WebKitWebContext.cpp
+++ b/Source/WebKit/UIProcess/API/glib/WebKitWebContext.cpp
@@ -119,9 +119,7 @@ enum {
     PROP_LOCAL_STORAGE_DIRECTORY,
 #endif
     PROP_WEBSITE_DATA_MANAGER,
-#if PLATFORM(GTK)
     PROP_PSON_ENABLED
-#endif
 };
 
 enum {
@@ -202,9 +200,7 @@ struct _WebKitWebContextPrivate {
 
     RefPtr<WebProcessPool> processPool;
     bool clientsDetached;
-#if PLATFORM(GTK)
     bool psonEnabled;
-#endif
 
     GRefPtr<WebKitFaviconDatabase> faviconDatabase;
     GRefPtr<WebKitSecurityManager> securityManager;
@@ -329,11 +325,9 @@ static void webkitWebContextGetProperty(GObject* object, guint propID, GValue* v
     case PROP_WEBSITE_DATA_MANAGER:
         g_value_set_object(value, webkit_web_context_get_website_data_manager(context));
         break;
-#if PLATFORM(GTK)
     case PROP_PSON_ENABLED:
         g_value_set_boolean(value, context->priv->psonEnabled);
         break;
-#endif
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, propID, paramSpec);
     }
@@ -354,11 +348,9 @@ static void webkitWebContextSetProperty(GObject* object, guint propID, const GVa
         context->priv->websiteDataManager = manager ? WEBKIT_WEBSITE_DATA_MANAGER(manager) : nullptr;
         break;
     }
-#if PLATFORM(GTK)
     case PROP_PSON_ENABLED:
         context->priv->psonEnabled = g_value_get_boolean(value);
         break;
-#endif
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, propID, paramSpec);
     }
@@ -375,9 +367,7 @@ static void webkitWebContextConstructed(GObject* object)
 
     API::ProcessPoolConfiguration configuration;
     configuration.setInjectedBundlePath(FileSystem::stringFromFileSystemRepresentation(bundleFilename.get()));
-#if PLATFORM(GTK)
     configuration.setProcessSwapsOnNavigation(priv->psonEnabled);
-#endif
 
     if (!priv->websiteDataManager)
         priv->websiteDataManager = adoptGRef(webkit_website_data_manager_new("local-storage-directory", priv->localStorageDirectory.data(), nullptr));
@@ -385,6 +375,11 @@ static void webkitWebContextConstructed(GObject* object)
     if (!webkit_website_data_manager_is_ephemeral(priv->websiteDataManager.get()))
         WebKit::LegacyGlobalSettings::singleton().setHSTSStorageDirectory(FileSystem::stringFromFileSystemRepresentation(webkit_website_data_manager_get_hsts_cache_directory(priv->websiteDataManager.get())));
 
+    const gchar *singleprocess = g_getenv("MINIBROWSER_SINGLEPROCESS");
+    if (singleprocess && *singleprocess) {
+        // processModel is not set at this point, force single process.
+        configuration.setUsesSingleWebProcess(true);
+    }
     priv->processPool = WebProcessPool::create(configuration);
     priv->processPool->setPrimaryDataStore(webkitWebsiteDataManagerGetDataStore(priv->websiteDataManager.get()));
     priv->processPool->setUserMessageHandler([webContext](UserMessage&& message, CompletionHandler<void(UserMessage&&)>&& completionHandler) {
@@ -496,7 +491,6 @@ static void webkit_web_context_class_init(WebKitWebContextClass* webContextClass
             WEBKIT_TYPE_WEBSITE_DATA_MANAGER,
             static_cast<GParamFlags>(WEBKIT_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY)));
 
-#if PLATFORM(GTK)
     /**
      * WebKitWebContext:process-swap-on-cross-site-navigation-enabled:
      *
@@ -519,7 +513,6 @@ static void webkit_web_context_class_init(WebKitWebContextClass* webContextClass
             _("Whether swap Web processes on cross-site navigations is enabled"),
             FALSE,
             static_cast<GParamFlags>(WEBKIT_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY)));
-#endif
 
     /**
      * WebKitWebContext::download-started:
diff --git a/Source/WebKit/UIProcess/API/glib/WebKitWebView.cpp b/Source/WebKit/UIProcess/API/glib/WebKitWebView.cpp
index 9633269039aed85e1993b234473509b4ecb39b79..34604cb5723f6ea0157923d2263612f1976f0b55 100644
--- a/Source/WebKit/UIProcess/API/glib/WebKitWebView.cpp
+++ b/Source/WebKit/UIProcess/API/glib/WebKitWebView.cpp
@@ -131,6 +131,7 @@ enum {
     CLOSE,
 
     SCRIPT_DIALOG,
+    SCRIPT_DIALOG_HANDLED,
 
     DECIDE_POLICY,
     PERMISSION_REQUEST,
@@ -1536,6 +1537,15 @@ static void webkit_web_view_class_init(WebKitWebViewClass* webViewClass)
         G_TYPE_BOOLEAN, 1,
         WEBKIT_TYPE_SCRIPT_DIALOG);
 
+    signals[SCRIPT_DIALOG_HANDLED] = g_signal_new(
+        "script-dialog-handled",
+        G_TYPE_FROM_CLASS(webViewClass),
+        G_SIGNAL_RUN_LAST,
+        G_STRUCT_OFFSET(WebKitWebViewClass, script_dialog),
+        g_signal_accumulator_true_handled, nullptr,
+        g_cclosure_marshal_generic,
+        G_TYPE_BOOLEAN, 1);
+
     /**
      * WebKitWebView::decide-policy:
      * @web_view: the #WebKitWebView on which the signal is emitted
@@ -2417,6 +2427,20 @@ void webkitWebViewRunJavaScriptBeforeUnloadConfirm(WebKitWebView* webView, const
     webkit_script_dialog_unref(webView->priv->currentScriptDialog);
 }
 
+void webkitWebViewHandleJavaScriptDialog(WebKitWebView* webView, bool accept, const String& value) {
+    auto* dialog = webView->priv->currentScriptDialog;
+    webkit_script_dialog_ref(dialog);
+    if (!value.isNull())
+        webkitWebViewSetCurrentScriptDialogUserInput(webView, value);
+    if (accept)
+        webkitWebViewAcceptCurrentScriptDialog(webView);
+    else
+        webkitWebViewDismissCurrentScriptDialog(webView);
+    gboolean returnValue;
+    g_signal_emit(webView, signals[SCRIPT_DIALOG_HANDLED], 0, dialog, &returnValue);
+    webkit_script_dialog_unref(dialog);
+}
+
 bool webkitWebViewIsShowingScriptDialog(WebKitWebView* webView)
 {
     if (!webView->priv->currentScriptDialog)
diff --git a/Source/WebKit/UIProcess/API/glib/WebKitWebViewPrivate.h b/Source/WebKit/UIProcess/API/glib/WebKitWebViewPrivate.h
index 5ab7574c9378f52db87ce75157627c04e9b2e962..5322d725238f5989c04b045615a2de8163329fdf 100644
--- a/Source/WebKit/UIProcess/API/glib/WebKitWebViewPrivate.h
+++ b/Source/WebKit/UIProcess/API/glib/WebKitWebViewPrivate.h
@@ -60,6 +60,7 @@ void webkitWebViewRunJavaScriptAlert(WebKitWebView*, const CString& message, Fun
 void webkitWebViewRunJavaScriptConfirm(WebKitWebView*, const CString& message, Function<void(bool)>&& completionHandler);
 void webkitWebViewRunJavaScriptPrompt(WebKitWebView*, const CString& message, const CString& defaultText, Function<void(const String&)>&& completionHandler);
 void webkitWebViewRunJavaScriptBeforeUnloadConfirm(WebKitWebView*, const CString& message, Function<void(bool)>&& completionHandler);
+void webkitWebViewHandleJavaScriptDialog(WebKitWebView*, bool accept, const String& value);
 bool webkitWebViewIsShowingScriptDialog(WebKitWebView*);
 bool webkitWebViewIsScriptDialogRunning(WebKitWebView*, WebKitScriptDialog*);
 String webkitWebViewGetCurrentScriptDialogMessage(WebKitWebView*);
diff --git a/Source/WebKit/UIProcess/API/gtk/PageClientImpl.cpp b/Source/WebKit/UIProcess/API/gtk/PageClientImpl.cpp
index a68a30983f609d925b45ee16fbe34110b6cabe95..533f45fe6810509b8a0e1823087011a86510770a 100644
--- a/Source/WebKit/UIProcess/API/gtk/PageClientImpl.cpp
+++ b/Source/WebKit/UIProcess/API/gtk/PageClientImpl.cpp
@@ -230,6 +230,8 @@ void PageClientImpl::doneWithKeyEvent(const NativeWebKeyboardEvent& event, bool
 {
     if (wasEventHandled)
         return;
+    if (!event.nativeEvent())
+        return;
 
     WebKitWebViewBase* webkitWebViewBase = WEBKIT_WEB_VIEW_BASE(m_viewWidget);
     webkitWebViewBaseForwardNextKeyEvent(webkitWebViewBase);
diff --git a/Source/WebKit/UIProcess/API/gtk/WebKitBrowserInspector.h b/Source/WebKit/UIProcess/API/gtk/WebKitBrowserInspector.h
new file mode 100644
index 0000000000000000000000000000000000000000..a51cfebc270ca5a91cd94645eeeb005ba9a67caf
--- /dev/null
+++ b/Source/WebKit/UIProcess/API/gtk/WebKitBrowserInspector.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if !defined(__WEBKIT2_H_INSIDE__) && !defined(WEBKIT2_COMPILATION)
+#error "Only <webkit2/webkit2.h> can be included directly."
+#endif
+
+#ifndef WebKitBrowserInspector_h
+#define WebKitBrowserInspector_h
+
+#include <glib-object.h>
+#include <webkit2/WebKitDefines.h>
+#include <webkit2/WebKitWebView.h>
+
+G_BEGIN_DECLS
+
+#define WEBKIT_TYPE_BROWSER_INSPECTOR            (webkit_browser_inspector_get_type())
+#define WEBKIT_BROWSER_INSPECTOR(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj), WEBKIT_TYPE_BROWSER_INSPECTOR, WebKitBrowserInspector))
+#define WEBKIT_IS_BROWSER_INSPECTOR(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), WEBKIT_TYPE_BROWSER_INSPECTOR))
+#define WEBKIT_BROWSER_INSPECTOR_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass),  WEBKIT_TYPE_BROWSER_INSPECTOR, WebKitBrowserInspectorClass))
+#define WEBKIT_IS_BROWSER_INSPECTOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),  WEBKIT_TYPE_BROWSER_INSPECTOR))
+#define WEBKIT_BROWSER_INSPECTOR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj),  WEBKIT_TYPE_BROWSER_INSPECTOR, WebKitBrowserInspectorClass))
+
+typedef struct _WebKitBrowserInspector        WebKitBrowserInspector;
+typedef struct _WebKitBrowserInspectorClass   WebKitBrowserInspectorClass;
+typedef struct _WebKitBrowserInspectorPrivate WebKitBrowserInspectorPrivate;
+
+struct _WebKitBrowserInspector {
+    GObject parent;
+
+    WebKitBrowserInspectorPrivate *priv;
+};
+
+struct _WebKitBrowserInspectorClass {
+    GObjectClass parent_class;
+
+    WebKitWebView *(* create_new_page)           (WebKitBrowserInspector    *browser_inspector,
+                                                  WebKitWebContext          *context);
+
+    void (*_webkit_reserved0) (void);
+    void (*_webkit_reserved1) (void);
+    void (*_webkit_reserved2) (void);
+    void (*_webkit_reserved3) (void);
+};
+
+WEBKIT_API GType
+webkit_browser_inspector_get_type                     (void);
+
+WEBKIT_API WebKitBrowserInspector *
+webkit_browser_inspector_get_default                  (void);
+
+WEBKIT_API void
+webkit_browser_inspector_initialize_pipe              (GMainLoop*);
+
+G_END_DECLS
+
+#endif
diff --git a/Source/WebKit/UIProcess/API/gtk/webkit2.h b/Source/WebKit/UIProcess/API/gtk/webkit2.h
index 930b17b6629e04d0dfa2222bbc3217877c6e1812..395462e5f01c195231e9296d1204167cded99ad3 100644
--- a/Source/WebKit/UIProcess/API/gtk/webkit2.h
+++ b/Source/WebKit/UIProcess/API/gtk/webkit2.h
@@ -32,6 +32,7 @@
 #include <webkit2/WebKitAutomationSession.h>
 #include <webkit2/WebKitBackForwardList.h>
 #include <webkit2/WebKitBackForwardListItem.h>
+#include <webkit2/WebKitBrowserInspector.h>
 #include <webkit2/WebKitContextMenu.h>
 #include <webkit2/WebKitContextMenuActions.h>
 #include <webkit2/WebKitContextMenuItem.h>
diff --git a/Source/WebKit/UIProcess/API/wpe/WebKitBrowserInspector.h b/Source/WebKit/UIProcess/API/wpe/WebKitBrowserInspector.h
new file mode 100644
index 0000000000000000000000000000000000000000..6dffa4fa10a9a64f778a0a77c760c2e76b2f9968
--- /dev/null
+++ b/Source/WebKit/UIProcess/API/wpe/WebKitBrowserInspector.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if !defined(__WEBKIT_H_INSIDE__) && !defined(WEBKIT2_COMPILATION)
+#error "Only <wpe/webkit.h> can be included directly."
+#endif
+
+#ifndef WebKitBrowserInspector_h
+#define WebKitBrowserInspector_h
+
+#include <glib-object.h>
+#include <wpe/WebKitDefines.h>
+#include <wpe/WebKitWebView.h>
+
+G_BEGIN_DECLS
+
+#define WEBKIT_TYPE_BROWSER_INSPECTOR            (webkit_browser_inspector_get_type())
+#define WEBKIT_BROWSER_INSPECTOR(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj), WEBKIT_TYPE_BROWSER_INSPECTOR, WebKitBrowserInspector))
+#define WEBKIT_IS_BROWSER_INSPECTOR(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), WEBKIT_TYPE_BROWSER_INSPECTOR))
+#define WEBKIT_BROWSER_INSPECTOR_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass),  WEBKIT_TYPE_BROWSER_INSPECTOR, WebKitBrowserInspectorClass))
+#define WEBKIT_IS_BROWSER_INSPECTOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),  WEBKIT_TYPE_BROWSER_INSPECTOR))
+#define WEBKIT_BROWSER_INSPECTOR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj),  WEBKIT_TYPE_BROWSER_INSPECTOR, WebKitBrowserInspectorClass))
+
+typedef struct _WebKitBrowserInspector        WebKitBrowserInspector;
+typedef struct _WebKitBrowserInspectorClass   WebKitBrowserInspectorClass;
+typedef struct _WebKitBrowserInspectorPrivate WebKitBrowserInspectorPrivate;
+
+struct _WebKitBrowserInspector {
+    GObject parent;
+
+    WebKitBrowserInspectorPrivate *priv;
+};
+
+struct _WebKitBrowserInspectorClass {
+    GObjectClass parent_class;
+
+    WebKitWebView *(* create_new_page)           (WebKitBrowserInspector    *browser_inspector,
+                                                  WebKitWebContext          *context);
+
+    void (*_webkit_reserved0) (void);
+    void (*_webkit_reserved1) (void);
+    void (*_webkit_reserved2) (void);
+    void (*_webkit_reserved3) (void);
+};
+
+WEBKIT_API GType
+webkit_browser_inspector_get_type                     (void);
+
+WEBKIT_API WebKitBrowserInspector *
+webkit_browser_inspector_get_default                  (void);
+
+WEBKIT_API void
+webkit_browser_inspector_initialize_pipe              (GMainLoop*);
+
+G_END_DECLS
+
+#endif
diff --git a/Source/WebKit/UIProcess/API/wpe/WebKitScriptDialogWPE.cpp b/Source/WebKit/UIProcess/API/wpe/WebKitScriptDialogWPE.cpp
index 3ad6e613657557045ec07ce4bcdb3eea0d1e7dae..a53a4aa01bd692ba34bacb9f663c335cfd3821a7 100644
--- a/Source/WebKit/UIProcess/API/wpe/WebKitScriptDialogWPE.cpp
+++ b/Source/WebKit/UIProcess/API/wpe/WebKitScriptDialogWPE.cpp
@@ -22,14 +22,26 @@
 
 #include "WebKitScriptDialogPrivate.h"
 
-void webkitScriptDialogAccept(WebKitScriptDialog*)
+void webkitScriptDialogAccept(WebKitScriptDialog* dialog)
 {
+    if (!dialog->completionHandler)
+        return;
+    auto completionHandler = std::exchange(dialog->completionHandler, nullptr);
+    completionHandler(true, String());
 }
 
-void webkitScriptDialogDismiss(WebKitScriptDialog*)
+void webkitScriptDialogDismiss(WebKitScriptDialog* dialog)
 {
+    if (!dialog->completionHandler)
+        return;
+    auto completionHandler = std::exchange(dialog->completionHandler, nullptr);
+    completionHandler(false, String());
 }
 
-void webkitScriptDialogSetUserInput(WebKitScriptDialog*, const String&)
+void webkitScriptDialogSetUserInput(WebKitScriptDialog* dialog, const String& value)
 {
+    if (!dialog->completionHandler)
+        return;
+    auto completionHandler = std::exchange(dialog->completionHandler, nullptr);
+    completionHandler(true, value);
 }
diff --git a/Source/WebKit/UIProcess/API/wpe/webkit.h b/Source/WebKit/UIProcess/API/wpe/webkit.h
index 02e258253e47fbf6594c20f743d0faeac8a4eefe..e051fdf396dc65717def6b36168b5538e3cb2f4d 100644
--- a/Source/WebKit/UIProcess/API/wpe/webkit.h
+++ b/Source/WebKit/UIProcess/API/wpe/webkit.h
@@ -32,6 +32,7 @@
 #include <wpe/WebKitAutomationSession.h>
 #include <wpe/WebKitBackForwardList.h>
 #include <wpe/WebKitBackForwardListItem.h>
+#include <wpe/WebKitBrowserInspector.h>
 #include <wpe/WebKitContextMenu.h>
 #include <wpe/WebKitContextMenuActions.h>
 #include <wpe/WebKitContextMenuItem.h>
diff --git a/Source/WebKit/UIProcess/BrowserInspectorController.cpp b/Source/WebKit/UIProcess/BrowserInspectorController.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5f4c95a9599141c98a1d12f4db12a5fbaf0cfcd7
--- /dev/null
+++ b/Source/WebKit/UIProcess/BrowserInspectorController.cpp
@@ -0,0 +1,238 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "BrowserInspectorController.h"
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "InspectorBrowserAgent.h"
+#include "InspectorBrowserAgentClient.h"
+#include "WebPageInspectorController.h"
+#include "WebPageProxy.h"
+#include "WebProcessPool.h"
+#include "WebProcessProxy.h"
+#include <JavaScriptCore/InspectorBackendDispatcher.h>
+#include <JavaScriptCore/InspectorBackendDispatchers.h>
+#include <JavaScriptCore/InspectorFrontendChannel.h>
+#include <JavaScriptCore/InspectorFrontendRouter.h>
+#include <JavaScriptCore/InspectorTarget.h>
+#include <wtf/Ref.h>
+#include <wtf/RefPtr.h>
+
+using namespace Inspector;
+
+namespace WebKit {
+
+static Vector<WebPageProxy*> allPages()
+{
+    ASSERT(isMainThread());
+    Vector<WebPageProxy*> result;
+    for (WebProcessPool* pool : WebProcessPool::allProcessPools()) {
+        for (auto& process : pool->processes()) {
+            result.appendRange(process->pages().begin(), process->pages().end());
+        }
+    }
+    return result;
+}
+
+class BrowserInspectorController::PageProxyChannel : public FrontendChannel {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    PageProxyChannel(FrontendChannel& frontendChannel, String pageProxyID, WebPageProxy& page)
+        : m_pageProxyID(pageProxyID)
+        , m_frontendChannel(frontendChannel)
+        , m_page(page)
+    {
+    }
+
+    ~PageProxyChannel() override = default;
+
+    void dispatchMessageFromFrontend(const String& message)
+    {
+        m_page.inspectorController().dispatchMessageFromFrontend(message);
+    }
+
+    WebPageProxy& page() { return m_page; }
+
+    void disconnect()
+    {
+        m_page.inspectorController().disconnectFrontend(*this);
+    }
+
+private:
+    ConnectionType connectionType() const override { return m_frontendChannel.connectionType(); }
+    void sendMessageToFrontend(const String& message) override
+    {
+        m_frontendChannel.sendMessageToFrontend(addTabIdToMessage(message));
+    }
+
+    String addTabIdToMessage(const String& message) {
+        RefPtr<JSON::Value> parsedMessage;
+        if (!JSON::Value::parseJSON(message, parsedMessage))
+            return message;
+
+        RefPtr<JSON::Object> messageObject;
+        if (!parsedMessage->asObject(messageObject))
+            return message;
+
+        messageObject->setString("pageProxyId"_s, m_pageProxyID);
+        return messageObject->toJSONString();
+    }
+
+    String m_pageProxyID;
+    FrontendChannel& m_frontendChannel;
+    WebPageProxy& m_page;
+};
+
+BrowserInspectorController::BrowserInspectorController(std::unique_ptr<InspectorBrowserAgentClient> client)
+    : m_frontendChannel(nullptr)
+    , m_frontendRouter(FrontendRouter::create())
+    , m_backendDispatcher(BackendDispatcher::create(m_frontendRouter.copyRef()))
+    , m_browserAgentClient(std::move(client))
+{
+    PageProxyIDMap* map = this;
+    auto browserAgent = makeUnique<InspectorBrowserAgent>(m_frontendRouter, m_backendDispatcher, m_browserAgentClient.get(), *map);
+    m_browserAgent = browserAgent.get();
+    m_agents.append(WTFMove(browserAgent));
+}
+
+BrowserInspectorController::~BrowserInspectorController()
+{
+    if (m_frontendChannel)
+        disconnectFrontend();
+}
+
+void BrowserInspectorController::connectFrontend(FrontendChannel& frontendChannel)
+{
+    ASSERT(!m_frontendChannel);
+    m_frontendChannel = &frontendChannel;
+    WebPageInspectorController::setObserver(this);
+
+    bool connectingFirstFrontend = !m_frontendRouter->hasFrontends();
+    m_frontendRouter->connectFrontend(frontendChannel);
+    if (connectingFirstFrontend)
+        m_agents.didCreateFrontendAndBackend(&m_frontendRouter.get(), &m_backendDispatcher.get());
+
+    connectToAllPages();
+}
+
+void BrowserInspectorController::disconnectFrontend()
+{
+    ASSERT(m_frontendChannel);
+    disconnectFromAllPages();
+
+    m_frontendRouter->disconnectFrontend(*m_frontendChannel);
+    if (!m_frontendRouter->hasFrontends())
+        m_agents.willDestroyFrontendAndBackend(DisconnectReason::InspectorDestroyed);
+
+    WebPageInspectorController::setObserver(nullptr);
+    m_frontendChannel = nullptr;
+}
+
+void BrowserInspectorController::dispatchMessageFromFrontend(const String& message)
+{
+    m_backendDispatcher->dispatch(message, BackendDispatcher::Mode::FailIfDomainIsMissing, [&](const RefPtr<JSON::Object>& messageObject) {
+        RefPtr<JSON::Value> pageProxyIDValue;
+        if (!messageObject->getValue("pageProxyId"_s, pageProxyIDValue))
+            return BackendDispatcher::DispatchResult::Continue;
+
+        String pageProxyID;
+        if (!pageProxyIDValue->asString(pageProxyID)) {
+            m_backendDispatcher->reportProtocolError(BackendDispatcher::InvalidRequest, "The type of 'pageProxyId' must be string"_s);
+            m_backendDispatcher->sendPendingErrors();
+            return BackendDispatcher::DispatchResult::Finished;
+        }
+
+
+        if (auto pageProxyChannel = m_pageProxyChannels.get(pageProxyID)) {
+            pageProxyChannel->dispatchMessageFromFrontend(message);
+            return BackendDispatcher::DispatchResult::Finished;
+        }
+
+        m_backendDispatcher->reportProtocolError(BackendDispatcher::InvalidRequest, "Cannot find page proxy with provided 'pageProxyId'"_s);
+        m_backendDispatcher->sendPendingErrors();
+        return BackendDispatcher::DispatchResult::Finished;
+    });
+}
+
+void BrowserInspectorController::connectToAllPages()
+{
+    for (auto* page : allPages())
+        connectToPage(*page);
+}
+
+void BrowserInspectorController::disconnectFromAllPages()
+{
+    for (auto it = m_pageProxyChannels.begin(); it != m_pageProxyChannels.end(); ++it)
+        it->value->disconnect();
+    m_pageProxyChannels.clear();
+}
+
+void BrowserInspectorController::connectToPage(WebPageProxy& page)
+{
+    String pageProxyID = InspectorBrowserAgent::toPageProxyIDProtocolString(page);
+    auto pageProxyChannel = makeUnique<PageProxyChannel>(*m_frontendChannel, pageProxyID, page);
+    page.inspectorController().connectFrontend(*pageProxyChannel);
+    // Always pause new targets if controlled remotely.
+    page.inspectorController().setPauseOnStart(true);
+    m_pageProxyChannels.set(pageProxyID, WTFMove(pageProxyChannel));
+}
+
+void BrowserInspectorController::didCreateInspectorController(WebPageProxy& page)
+{
+    ASSERT(m_frontendChannel);
+    // Auto-connect to all new pages.
+    connectToPage(page);
+    m_browserAgent->didCreateWebPageProxy(page);
+}
+
+void BrowserInspectorController::willDestroyInspectorController(WebPageProxy& page)
+{
+    m_browserAgent->willDestroyWebPageProxy(page);
+
+    String pageProxyID = InspectorBrowserAgent::toPageProxyIDProtocolString(page);
+    auto it = m_pageProxyChannels.find(pageProxyID);
+    ASSERT(it != m_pageProxyChannels.end());
+    it->value->disconnect();
+    m_pageProxyChannels.remove(it);
+}
+
+void BrowserInspectorController::didFailProvisionalLoad(WebPageProxy& page, uint64_t navigationID, const String& error)
+{
+    m_browserAgent->didFailProvisionalLoad(page, navigationID, error);
+}
+
+WebPageProxy* BrowserInspectorController::findPageProxy(const String& pageProxyID)
+{
+    if (auto* pageProxyChannel = m_pageProxyChannels.get(pageProxyID))
+        return &pageProxyChannel->page();
+
+    return nullptr;
+}
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/BrowserInspectorController.h b/Source/WebKit/UIProcess/BrowserInspectorController.h
new file mode 100644
index 0000000000000000000000000000000000000000..a6ee1aaaaee4a42ec7afb409c74d3cc3d8eefcd0
--- /dev/null
+++ b/Source/WebKit/UIProcess/BrowserInspectorController.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "InspectorBrowserAgent.h"
+#include "WebPageInspectorController.h"
+#include <JavaScriptCore/InspectorAgentRegistry.h>
+#include <wtf/Forward.h>
+#include <wtf/Noncopyable.h>
+
+namespace Inspector {
+class BackendDispatcher;
+class FrontendChannel;
+class FrontendRouter;
+}
+
+namespace WebKit {
+
+class InspectorBrowserAgent;
+class InspectorBrowserAgentClient;
+
+class BrowserInspectorController : private WebPageInspectorControllerObserver, private PageProxyIDMap {
+    WTF_MAKE_NONCOPYABLE(BrowserInspectorController);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    BrowserInspectorController(std::unique_ptr<InspectorBrowserAgentClient> client);
+    ~BrowserInspectorController();
+
+    void connectFrontend(Inspector::FrontendChannel&);
+    void disconnectFrontend();
+    void dispatchMessageFromFrontend(const String& message);
+
+private:
+    class TargetHandler;
+    class PageProxyChannel;
+
+    // WebPageInspectorControllerObserver
+    void didCreateInspectorController(WebPageProxy&) override;
+    void willDestroyInspectorController(WebPageProxy&) override;
+    void didFailProvisionalLoad(WebPageProxy&, uint64_t navigationID, const String& error) override;
+
+    // PageProxyIDMap
+    WebPageProxy* findPageProxy(const String& pageProxyID) override;
+
+    void connectToAllPages();
+    void disconnectFromAllPages();
+    void connectToPage(WebPageProxy&);
+
+    Inspector::FrontendChannel* m_frontendChannel { nullptr };
+    Ref<Inspector::FrontendRouter> m_frontendRouter;
+    Ref<Inspector::BackendDispatcher> m_backendDispatcher;
+    std::unique_ptr<InspectorBrowserAgentClient> m_browserAgentClient;
+    Inspector::AgentRegistry m_agents;
+    InspectorBrowserAgent* m_browserAgent { nullptr };
+    HashMap<String, std::unique_ptr<PageProxyChannel>> m_pageProxyChannels;
+};
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/BrowserInspectorPipe.cpp b/Source/WebKit/UIProcess/BrowserInspectorPipe.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..ff2aa2f85ece80f9bf029ca7b54cc42835a253c7
--- /dev/null
+++ b/Source/WebKit/UIProcess/BrowserInspectorPipe.cpp
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "BrowserInspectorPipe.h"
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "BrowserInspectorController.h"
+#include "RemoteInspectorPipe.h"
+#include <wtf/NeverDestroyed.h>
+#include "InspectorBrowserAgentClient.h"
+
+namespace WebKit {
+
+void initializeBrowserInspectorPipe(std::unique_ptr<InspectorBrowserAgentClient> client)
+{
+    class BrowserInspectorPipe {
+    public:
+        BrowserInspectorPipe(std::unique_ptr<InspectorBrowserAgentClient> client)
+            : m_browserInspectorController(std::move(client))
+            , m_remoteInspectorPipe(m_browserInspectorController)
+        {
+        }
+
+        BrowserInspectorController m_browserInspectorController;
+        RemoteInspectorPipe m_remoteInspectorPipe;
+    };
+
+    static NeverDestroyed<BrowserInspectorPipe> pipe(std::move(client));
+}
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/BrowserInspectorPipe.h b/Source/WebKit/UIProcess/BrowserInspectorPipe.h
new file mode 100644
index 0000000000000000000000000000000000000000..7dd8ee18d2310935db1a9cb6cbc48b7fb4e24f47
--- /dev/null
+++ b/Source/WebKit/UIProcess/BrowserInspectorPipe.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+namespace WebKit {
+
+class InspectorBrowserAgentClient;
+
+void initializeBrowserInspectorPipe(std::unique_ptr<InspectorBrowserAgentClient> client);
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/Cocoa/SOAuthorization/PopUpSOAuthorizationSession.h b/Source/WebKit/UIProcess/Cocoa/SOAuthorization/PopUpSOAuthorizationSession.h
index 454c61ffdefecc476d1560c7c43f5b5d345f281d..6de7509037b7683ddd403ee247bdf2845ce4e87a 100644
--- a/Source/WebKit/UIProcess/Cocoa/SOAuthorization/PopUpSOAuthorizationSession.h
+++ b/Source/WebKit/UIProcess/Cocoa/SOAuthorization/PopUpSOAuthorizationSession.h
@@ -27,6 +27,8 @@
 
 #if HAVE(APP_SSO)
 
+#include <wtf/Forward.h>
+#include <wtf/CompletionHandler.h>
 #include "SOAuthorizationSession.h"
 #include <wtf/CompletionHandler.h>
 
@@ -39,6 +41,8 @@ class NavigationAction;
 
 namespace WebKit {
 
+class WebPageProxy;
+
 // FSM: Idle => Active => Completed
 class PopUpSOAuthorizationSession final : public SOAuthorizationSession {
 public:
diff --git a/Source/WebKit/UIProcess/Cocoa/SOAuthorization/PopUpSOAuthorizationSession.mm b/Source/WebKit/UIProcess/Cocoa/SOAuthorization/PopUpSOAuthorizationSession.mm
index 0f18038de989e69a8432c85b71b6c04e931302b3..82a966779403346aed174dcfcd01a79691956d7b 100644
--- a/Source/WebKit/UIProcess/Cocoa/SOAuthorization/PopUpSOAuthorizationSession.mm
+++ b/Source/WebKit/UIProcess/Cocoa/SOAuthorization/PopUpSOAuthorizationSession.mm
@@ -29,6 +29,7 @@
 #if HAVE(APP_SSO)
 
 #import "APINavigationAction.h"
+#import "WebPageProxy.h"
 #import "WKNavigationDelegatePrivate.h"
 #import "WKUIDelegate.h"
 #import "WKWebViewConfigurationPrivate.h"
diff --git a/Source/WebKit/UIProcess/Cocoa/UIDelegate.h b/Source/WebKit/UIProcess/Cocoa/UIDelegate.h
index a3593adf44b8d34a7c461c6b29332ba96f67992b..74661155eaa1dd6a9aa6bd177564dbeee7415019 100644
--- a/Source/WebKit/UIProcess/Cocoa/UIDelegate.h
+++ b/Source/WebKit/UIProcess/Cocoa/UIDelegate.h
@@ -91,6 +91,7 @@ private:
         void runJavaScriptAlert(WebPageProxy&, const WTF::String&, WebFrameProxy*, WebCore::SecurityOriginData&&, Function<void()>&& completionHandler) final;
         void runJavaScriptConfirm(WebPageProxy&, const WTF::String&, WebFrameProxy*, WebCore::SecurityOriginData&&, Function<void(bool)>&& completionHandler) final;
         void runJavaScriptPrompt(WebPageProxy&, const WTF::String&, const WTF::String&, WebFrameProxy*, WebCore::SecurityOriginData&&, Function<void(const WTF::String&)>&&) final;
+        void handleJavaScriptDialog(WebKit::WebPageProxy&, bool accept, const WTF::String&) final;
         void presentStorageAccessConfirmDialog(const WTF::String& requestingDomain, const WTF::String& currentDomain, CompletionHandler<void(bool)>&&);
         void requestStorageAccessConfirm(WebPageProxy&, WebFrameProxy*, const WebCore::RegistrableDomain& requestingDomain, const WebCore::RegistrableDomain& currentDomain, CompletionHandler<void(bool)>&&) final;
         void decidePolicyForGeolocationPermissionRequest(WebPageProxy&, WebFrameProxy&, API::SecurityOrigin&, Function<void(bool)>&) final;
@@ -171,6 +172,7 @@ private:
         bool webViewRunJavaScriptAlertPanelWithMessageInitiatedByFrameCompletionHandler : 1;
         bool webViewRunJavaScriptConfirmPanelWithMessageInitiatedByFrameCompletionHandler : 1;
         bool webViewRunJavaScriptTextInputPanelWithPromptDefaultTextInitiatedByFrameCompletionHandler : 1;
+        bool webViewHandleJavaScriptDialogValue : 1;
         bool webViewRequestStorageAccessPanelUnderFirstPartyCompletionHandler : 1;
         bool webViewRunBeforeUnloadConfirmPanelWithMessageInitiatedByFrameCompletionHandler : 1;
         bool webViewRequestGeolocationPermissionForFrameDecisionHandler : 1;
diff --git a/Source/WebKit/UIProcess/Cocoa/UIDelegate.mm b/Source/WebKit/UIProcess/Cocoa/UIDelegate.mm
index a3d0ded6df0566cb74493f98ec28bce0e8d893b3..a4d9a214407eb2c55c07a10b700abbb268768909 100644
--- a/Source/WebKit/UIProcess/Cocoa/UIDelegate.mm
+++ b/Source/WebKit/UIProcess/Cocoa/UIDelegate.mm
@@ -104,6 +104,7 @@ void UIDelegate::setDelegate(id <WKUIDelegate> delegate)
     m_delegateMethods.webViewRunJavaScriptAlertPanelWithMessageInitiatedByFrameCompletionHandler = [delegate respondsToSelector:@selector(webView:runJavaScriptAlertPanelWithMessage:initiatedByFrame:completionHandler:)];
     m_delegateMethods.webViewRunJavaScriptConfirmPanelWithMessageInitiatedByFrameCompletionHandler = [delegate respondsToSelector:@selector(webView:runJavaScriptConfirmPanelWithMessage:initiatedByFrame:completionHandler:)];
     m_delegateMethods.webViewRunJavaScriptTextInputPanelWithPromptDefaultTextInitiatedByFrameCompletionHandler = [delegate respondsToSelector:@selector(webView:runJavaScriptTextInputPanelWithPrompt:defaultText:initiatedByFrame:completionHandler:)];
+    m_delegateMethods.webViewHandleJavaScriptDialogValue = [delegate respondsToSelector:@selector(webView:handleJavaScriptDialog:value:)];
     m_delegateMethods.webViewRequestStorageAccessPanelUnderFirstPartyCompletionHandler = [delegate respondsToSelector:@selector(_webView:requestStorageAccessPanelForDomain:underCurrentDomain:completionHandler:)];
     m_delegateMethods.webViewRunBeforeUnloadConfirmPanelWithMessageInitiatedByFrameCompletionHandler = [delegate respondsToSelector:@selector(_webView:runBeforeUnloadConfirmPanelWithMessage:initiatedByFrame:completionHandler:)];
     m_delegateMethods.webViewRequestGeolocationPermissionForFrameDecisionHandler = [delegate respondsToSelector:@selector(_webView:requestGeolocationPermissionForFrame:decisionHandler:)];
@@ -341,6 +342,15 @@ void UIDelegate::UIClient::runJavaScriptPrompt(WebPageProxy&, const WTF::String&
     }).get()];
 }
 
+void UIDelegate::UIClient::handleJavaScriptDialog(WebKit::WebPageProxy&, bool accept, const WTF::String& value) {
+    if (!m_uiDelegate.m_delegateMethods.webViewHandleJavaScriptDialogValue)
+        return;
+    auto delegate = m_uiDelegate.m_delegate.get();
+    if (!delegate)
+        return;
+    [delegate webView:m_uiDelegate.m_webView handleJavaScriptDialog:accept value:value];
+}
+
 void UIDelegate::UIClient::requestStorageAccessConfirm(WebPageProxy&, WebFrameProxy*, const WebCore::RegistrableDomain& requestingDomain, const WebCore::RegistrableDomain& currentDomain, CompletionHandler<void(bool)>&& completionHandler)
 {
     auto delegate = m_uiDelegate.m_delegate.get();
diff --git a/Source/WebKit/UIProcess/Cocoa/WebProcessPoolCocoa.mm b/Source/WebKit/UIProcess/Cocoa/WebProcessPoolCocoa.mm
index d3bea9e4356262d5fdd5991f3965e9e80e6041f6..81b603d6c40591a824dc2d63f2d860c2ebb57e92 100644
--- a/Source/WebKit/UIProcess/Cocoa/WebProcessPoolCocoa.mm
+++ b/Source/WebKit/UIProcess/Cocoa/WebProcessPoolCocoa.mm
@@ -137,6 +137,13 @@ static void registerUserDefaultsIfNeeded()
     [[NSUserDefaults standardUserDefaults] registerDefaults:registrationDictionary];
 }
 
+void WebProcessPool::setIgnoreTLSErrors(bool ignoreTLSErrors)
+{
+    m_ignoreTLSErrors = ignoreTLSErrors;
+    if (m_networkProcess)
+        m_networkProcess->send(Messages::NetworkProcess::SetIgnoreTLSErrors(m_ignoreTLSErrors), 0);
+}
+
 void WebProcessPool::updateProcessSuppressionState()
 {
     if (m_networkProcess)
@@ -357,7 +364,7 @@ void WebProcessPool::platformInitializeWebProcess(const WebProcessProxy& process
 #if PLATFORM(MAC)
     auto screenProperties = WebCore::collectScreenProperties();
     parameters.screenProperties = WTFMove(screenProperties);
-    parameters.useOverlayScrollbars = ([NSScroller preferredScrollerStyle] == NSScrollerStyleOverlay);
+    parameters.useOverlayScrollbars = m_configuration->forceOverlayScrollbars() || ([NSScroller preferredScrollerStyle] == NSScrollerStyleOverlay);
 #endif
     
 #if PLATFORM(IOS)
@@ -451,6 +458,8 @@ void WebProcessPool::platformInitializeNetworkProcess(NetworkProcessCreationPara
         }
     }
 
+    parameters.ignoreTLSErrors = m_ignoreTLSErrors;
+
     parameters.networkATSContext = adoptCF(_CFNetworkCopyATSContext());
 
     parameters.shouldSuppressMemoryPressureHandler = [defaults boolForKey:WebKitSuppressMemoryPressureHandlerDefaultsKey];
@@ -611,8 +620,8 @@ void WebProcessPool::registerNotificationObservers()
 
 #if ENABLE(WEBPROCESS_WINDOWSERVER_BLOCKING)
     m_scrollerStyleNotificationObserver = [[NSNotificationCenter defaultCenter] addObserverForName:NSPreferredScrollerStyleDidChangeNotification object:nil queue:[NSOperationQueue currentQueue] usingBlock:^(NSNotification *notification) {
-        auto scrollbarStyle = [NSScroller preferredScrollerStyle];
-        sendToAllProcesses(Messages::WebProcess::ScrollerStylePreferenceChanged(scrollbarStyle));
+        bool useOverlayScrollbars = m_configuration->forceOverlayScrollbars() || ([NSScroller preferredScrollerStyle] == NSScrollerStyleOverlay);
+        sendToAllProcesses(Messages::WebProcess::ScrollerStylePreferenceChanged(useOverlayScrollbars));
     }];
 #endif
 
diff --git a/Source/WebKit/UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.cpp b/Source/WebKit/UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.cpp
index 6bbd1cabd27ae2847648a8c2edcf9acfcd556ff5..38d101b9a96986e40f6e9f0261fa429a3d516e2e 100644
--- a/Source/WebKit/UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.cpp
+++ b/Source/WebKit/UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.cpp
@@ -37,6 +37,7 @@
 #include "WebProcessProxy.h"
 #include <WebCore/PlatformDisplay.h>
 #include <WebCore/Region.h>
+#include <wtf/Vector.h>
 
 #if PLATFORM(GTK)
 #include <gtk/gtk.h>
@@ -119,6 +120,10 @@ void DrawingAreaProxyCoordinatedGraphics::paint(BackingStore::PlatformGraphicsCo
 
 void DrawingAreaProxyCoordinatedGraphics::sizeDidChange()
 {
+    for (auto& value : m_callbacks)
+        value();
+    m_callbacks.clear();
+
 #if USE(DIRECT2D)
     m_backingStore = nullptr;
 #endif
@@ -133,6 +138,11 @@ void DrawingAreaProxyCoordinatedGraphics::deviceScaleFactorDidChange()
     backingStoreStateDidChange(RespondImmediately);
 }
 
+void DrawingAreaProxyCoordinatedGraphics::waitForSizeUpdate(Function<void ()>&& callback)
+{
+    m_callbacks.append(WTFMove(callback));
+}
+
 void DrawingAreaProxyCoordinatedGraphics::waitForBackingStoreUpdateOnNextPaint()
 {
     m_hasReceivedFirstUpdate = true;
diff --git a/Source/WebKit/UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.h b/Source/WebKit/UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.h
index d7695088e7cfc4f638f157338754f9f157489749..ba114d47ac079661702e44f19853398f5c1d6b55 100644
--- a/Source/WebKit/UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.h
+++ b/Source/WebKit/UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.h
@@ -30,6 +30,7 @@
 #include "BackingStore.h"
 #include "DrawingAreaProxy.h"
 #include "LayerTreeContext.h"
+#include <wtf/HashMap.h>
 #include <wtf/RunLoop.h>
 
 namespace WebCore {
@@ -49,6 +50,7 @@ public:
 
     bool isInAcceleratedCompositingMode() const { return !m_layerTreeContext.isEmpty(); }
     const LayerTreeContext& layerTreeContext() const { return m_layerTreeContext; }
+    void waitForSizeUpdate(Function<void ()>&&);
 
 private:
     // DrawingAreaProxy
@@ -126,6 +128,8 @@ private:
     // For a new Drawing Area don't draw anything until the WebProcess has sent over the first content.
     bool m_hasReceivedFirstUpdate { false };
 
+    Vector<Function<void ()>> m_callbacks;
+
 #if !PLATFORM(WPE)
     bool m_isBackingStoreDiscardable { true };
     std::unique_ptr<BackingStore> m_backingStore;
diff --git a/Source/WebKit/UIProcess/DrawingAreaProxy.h b/Source/WebKit/UIProcess/DrawingAreaProxy.h
index 4896c404bc8b25d69360de7d1c509383282b2317..14bdebf732e929ea367c961f9d0bec85202bbae3 100644
--- a/Source/WebKit/UIProcess/DrawingAreaProxy.h
+++ b/Source/WebKit/UIProcess/DrawingAreaProxy.h
@@ -70,6 +70,7 @@ public:
 
     const WebCore::IntSize& size() const { return m_size; }
     bool setSize(const WebCore::IntSize&, const WebCore::IntSize& scrollOffset = { });
+    void waitForSizeUpdate(Function<void ()>&&);
 
     // The timeout we use when waiting for a DidUpdateGeometry message.
     static constexpr Seconds didUpdateBackingStoreStateTimeout() { return Seconds::fromMilliseconds(500); }
diff --git a/Source/WebKit/UIProcess/Inspector/InspectorTargetProxy.cpp b/Source/WebKit/UIProcess/Inspector/InspectorTargetProxy.cpp
index 6928ca2fbfb6939062e3cd14bb7ba6f2fdc87f5f..c4645302296540a408aa88dabb64fd5e9a04f3f7 100644
--- a/Source/WebKit/UIProcess/Inspector/InspectorTargetProxy.cpp
+++ b/Source/WebKit/UIProcess/Inspector/InspectorTargetProxy.cpp
@@ -27,11 +27,10 @@
 #include "InspectorTargetProxy.h"
 
 #include "ProvisionalPageProxy.h"
-#include "WebFrameProxy.h"
+#include "WebPageInspectorController.h"
 #include "WebPageInspectorTarget.h"
 #include "WebPageMessages.h"
 #include "WebPageProxy.h"
-#include "WebProcessProxy.h"
 
 namespace WebKit {
 
@@ -39,18 +38,17 @@ using namespace Inspector;
 
 std::unique_ptr<InspectorTargetProxy> InspectorTargetProxy::create(WebPageProxy& page, const String& targetId, Inspector::InspectorTargetType type)
 {
-    return makeUnique<InspectorTargetProxy>(page, targetId, type);
+    return makeUnique<InspectorTargetProxy>(page, nullptr, targetId, type);
 }
 
-std::unique_ptr<InspectorTargetProxy> InspectorTargetProxy::create(ProvisionalPageProxy& provisionalPage, const String& targetId, Inspector::InspectorTargetType type)
+std::unique_ptr<InspectorTargetProxy> InspectorTargetProxy::create(ProvisionalPageProxy& provisionalPage, const String& targetId)
 {
-    auto target = InspectorTargetProxy::create(provisionalPage.page(), targetId, type);
-    target->m_provisionalPage = makeWeakPtr(provisionalPage);
-    return target;
+    return makeUnique<InspectorTargetProxy>(provisionalPage.page(), &provisionalPage, targetId, Inspector::InspectorTargetType::Page);
 }
 
-InspectorTargetProxy::InspectorTargetProxy(WebPageProxy& page, const String& targetId, Inspector::InspectorTargetType type)
+InspectorTargetProxy::InspectorTargetProxy(WebPageProxy& page, ProvisionalPageProxy* provisionalPage, const String& targetId, Inspector::InspectorTargetType type)
     : m_page(page)
+    , m_provisionalPage(makeWeakPtr(provisionalPage))
     , m_identifier(targetId)
     , m_type(type)
 {
@@ -83,6 +81,9 @@ void InspectorTargetProxy::disconnect()
 
 void InspectorTargetProxy::sendMessageToTargetBackend(const String& message)
 {
+    if (m_page.inspectorController().dispatchMessageToTargetBackend(message))
+        return;
+
     if (m_provisionalPage) {
         m_provisionalPage->send(Messages::WebPage::SendMessageToTargetBackend(identifier(), message));
         return;
@@ -97,6 +98,31 @@ void InspectorTargetProxy::didCommitProvisionalTarget()
     m_provisionalPage = nullptr;
 }
 
+void InspectorTargetProxy::willResume()
+{
+    if (m_page.hasRunningProcess())
+        m_page.send(Messages::WebPage::ResumeInspectorIfPausedInNewWindow());
+}
+
+void InspectorTargetProxy::activate(String& error)
+{
+    if (m_type != Inspector::InspectorTargetType::Page)
+        return InspectorTarget::activate(error);
+
+    platformActivate(error);
+}
+
+void InspectorTargetProxy::close(String& error, bool runBeforeUnload)
+{
+    if (m_type != Inspector::InspectorTargetType::Page)
+        return InspectorTarget::close(error, runBeforeUnload);
+
+    if (runBeforeUnload)
+        m_page.tryClose();
+    else
+        m_page.closePage();
+}
+
 bool InspectorTargetProxy::isProvisional() const
 {
     return !!m_provisionalPage;
diff --git a/Source/WebKit/UIProcess/Inspector/InspectorTargetProxy.h b/Source/WebKit/UIProcess/Inspector/InspectorTargetProxy.h
index a2239cec8e18850f35f7f88a9c4ebadc62bf4023..79f3ff84327dc075ec96983e04db4b10343b7fae 100644
--- a/Source/WebKit/UIProcess/Inspector/InspectorTargetProxy.h
+++ b/Source/WebKit/UIProcess/Inspector/InspectorTargetProxy.h
@@ -37,13 +37,13 @@ class WebPageProxy;
 // NOTE: This UIProcess side InspectorTarget doesn't care about the frontend channel, since
 // any target -> frontend messages will be routed to the WebPageProxy with a targetId.
 
-class InspectorTargetProxy final : public Inspector::InspectorTarget {
+class InspectorTargetProxy : public Inspector::InspectorTarget {
     WTF_MAKE_FAST_ALLOCATED;
     WTF_MAKE_NONCOPYABLE(InspectorTargetProxy);
 public:
     static std::unique_ptr<InspectorTargetProxy> create(WebPageProxy&, const String& targetId, Inspector::InspectorTargetType);
-    static std::unique_ptr<InspectorTargetProxy> create(ProvisionalPageProxy&, const String& targetId, Inspector::InspectorTargetType);
-    InspectorTargetProxy(WebPageProxy&, const String& targetId, Inspector::InspectorTargetType);
+    static std::unique_ptr<InspectorTargetProxy> create(ProvisionalPageProxy&, const String& targetId);
+    InspectorTargetProxy(WebPageProxy&, ProvisionalPageProxy*, const String& targetId, Inspector::InspectorTargetType);
     ~InspectorTargetProxy() = default;
 
     Inspector::InspectorTargetType type() const final { return m_type; }
@@ -55,12 +55,17 @@ public:
     void connect(Inspector::FrontendChannel::ConnectionType) override;
     void disconnect() override;
     void sendMessageToTargetBackend(const String&) override;
+    void activate(String& error) override;
+    void close(String& error, bool runBeforeUnload) override;
 
 private:
+    void willResume() override;
+    void platformActivate(String& error) const;
+
     WebPageProxy& m_page;
+    WeakPtr<ProvisionalPageProxy> m_provisionalPage;
     String m_identifier;
     Inspector::InspectorTargetType m_type;
-    WeakPtr<ProvisionalPageProxy> m_provisionalPage;
 };
 
 } // namespace WebKit
diff --git a/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.cpp b/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.cpp
index 1ee28bf716374371433215148aa20a51927a8a33..a41732eb550bc4079ae14d2cbd2c3b082e1fda73 100644
--- a/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.cpp
+++ b/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.cpp
@@ -26,10 +26,16 @@
 #include "config.h"
 #include "WebPageInspectorController.h"
 
+#include "APINavigation.h"
+#include "InspectorDialogAgent.h"
 #include "ProvisionalPageProxy.h"
 #include "WebFrameProxy.h"
+#include "WebPageInspectorEmulationAgent.h"
+#include "WebPageInspectorInputAgent.h"
 #include "WebPageInspectorTarget.h"
 #include "WebPageProxy.h"
+#include "WebPreferences.h"
+#include <WebCore/ResourceError.h>
 #include <JavaScriptCore/InspectorAgentBase.h>
 #include <JavaScriptCore/InspectorBackendDispatcher.h>
 #include <JavaScriptCore/InspectorBackendDispatchers.h>
@@ -46,29 +52,98 @@ static String getTargetID(const ProvisionalPageProxy& provisionalPage)
     return WebPageInspectorTarget::toTargetID(provisionalPage.webPageID());
 }
 
+WebPageInspectorControllerObserver* WebPageInspectorController::s_observer = nullptr;
+
+void WebPageInspectorController::setObserver(WebPageInspectorControllerObserver* observer)
+{
+    s_observer = observer;
+}
+
 WebPageInspectorController::WebPageInspectorController(WebPageProxy& page)
     : m_page(page)
     , m_frontendRouter(FrontendRouter::create())
     , m_backendDispatcher(BackendDispatcher::create(m_frontendRouter.copyRef()))
+{
+}
+
+void WebPageInspectorController::init()
 {
     auto targetAgent = makeUnique<InspectorTargetAgent>(m_frontendRouter.get(), m_backendDispatcher.get());
 
     m_targetAgent = targetAgent.get();
 
     m_agents.append(WTFMove(targetAgent));
+    auto emulationAgent = makeUnique<WebPageInspectorEmulationAgent>(m_backendDispatcher.get(), m_page);
+    m_emulationAgent = emulationAgent.get();
+    m_agents.append(WTFMove(emulationAgent));
+    auto inputAgent = makeUnique<WebPageInspectorInputAgent>(m_backendDispatcher.get(), m_page);
+    m_inputAgent = inputAgent.get();
+    m_agents.append(WTFMove(inputAgent));
+    m_agents.append(makeUnique<InspectorDialogAgent>(m_backendDispatcher.get(), m_frontendRouter.get(), m_page));
+
+    if (s_observer)
+        s_observer->didCreateInspectorController(m_page);
+
+    // window.open will create page with already running process.
+    if (!m_page.hasRunningProcess())
+        return;
+    String pageTargetId = WebPageInspectorTarget::toTargetID(m_page.webPageID());
+    createInspectorTarget(pageTargetId, Inspector::InspectorTargetType::Page);
 }
 
-void WebPageInspectorController::init()
+void WebPageInspectorController::didFinishAttachingToWebProcess()
 {
-    String pageTargetId = WebPageInspectorTarget::toTargetID(m_page.webPageID());
-    createInspectorTarget(pageTargetId, Inspector::InspectorTargetType::Page);
+    String pageTargetID = WebPageInspectorTarget::toTargetID(m_page.webPageID());
+    // Create target only after attaching to a Web Process first time. Before that
+    // we cannot event establish frontend connection.
+    if (m_targets.contains(pageTargetID))
+        return;
+    createInspectorTarget(pageTargetID, Inspector::InspectorTargetType::Page);
 }
 
 void WebPageInspectorController::pageClosed()
 {
+    String pageTargetId = WebPageInspectorTarget::toTargetID(m_page.webPageID());
+    destroyInspectorTarget(pageTargetId);
+
     disconnectAllFrontends();
 
     m_agents.discardValues();
+
+    if (s_observer)
+        s_observer->willDestroyInspectorController(m_page);
+}
+
+bool WebPageInspectorController::pageCrashed(ProcessTerminationReason reason)
+{
+    if (reason != ProcessTerminationReason::Crash)
+        return false;
+    String targetId = WebPageInspectorTarget::toTargetID(m_page.webPageID());
+    auto it = m_targets.find(targetId);
+    if (it == m_targets.end())
+        return false;
+    m_targetAgent->targetCrashed(*it->value);
+    m_targets.remove(it);
+
+    return m_targetAgent->isConnected();
+}
+
+void WebPageInspectorController::didShowPage()
+{
+    if (m_frontendRouter->hasFrontends())
+        m_emulationAgent->didShowPage();
+}
+
+void WebPageInspectorController::didProcessAllPendingKeyboardEvents()
+{
+    if (m_frontendRouter->hasFrontends())
+        m_inputAgent->didProcessAllPendingKeyboardEvents();
+}
+
+void WebPageInspectorController::didProcessAllPendingMouseEvents()
+{
+    if (m_frontendRouter->hasFrontends())
+        m_inputAgent->didProcessAllPendingMouseEvents();
 }
 
 bool WebPageInspectorController::hasLocalFrontend() const
@@ -80,6 +155,17 @@ void WebPageInspectorController::connectFrontend(Inspector::FrontendChannel& fro
 {
     bool connectingFirstFrontend = !m_frontendRouter->hasFrontends();
 
+    // HACK: forcefully disconnect remote connections to show local inspector starting with initial
+    // agents' state.
+    if (frontendChannel.connectionType() == Inspector::FrontendChannel::ConnectionType::Local &&
+        !connectingFirstFrontend && !m_frontendRouter->hasLocalFrontend()) {
+        disconnectAllFrontends();
+        connectingFirstFrontend = true;
+    }
+
+    if (connectingFirstFrontend)
+        adjustPageSettings();
+
     m_frontendRouter->connectFrontend(frontendChannel);
 
     if (connectingFirstFrontend)
@@ -98,8 +184,10 @@ void WebPageInspectorController::disconnectFrontend(FrontendChannel& frontendCha
     m_frontendRouter->disconnectFrontend(frontendChannel);
 
     bool disconnectingLastFrontend = !m_frontendRouter->hasFrontends();
-    if (disconnectingLastFrontend)
+    if (disconnectingLastFrontend) {
         m_agents.willDestroyFrontendAndBackend(DisconnectReason::InspectorDestroyed);
+        m_pendingNavigations.clear();
+    }
 
     m_page.didChangeInspectorFrontendCount(m_frontendRouter->frontendCount());
 
@@ -122,6 +210,8 @@ void WebPageInspectorController::disconnectAllFrontends()
     // Disconnect any remaining remote frontends.
     m_frontendRouter->disconnectAllFrontends();
 
+    m_pendingNavigations.clear();
+
     m_page.didChangeInspectorFrontendCount(m_frontendRouter->frontendCount());
 
 #if ENABLE(REMOTE_INSPECTOR)
@@ -134,6 +224,11 @@ void WebPageInspectorController::dispatchMessageFromFrontend(const String& messa
     m_backendDispatcher->dispatch(message);
 }
 
+bool WebPageInspectorController::dispatchMessageToTargetBackend(const String& message)
+{
+    return m_backendDispatcher->dispatch(message, BackendDispatcher::Mode::ContinueIfDomainIsMissing) == BackendDispatcher::DispatchResult::Finished;
+}
+
 #if ENABLE(REMOTE_INSPECTOR)
 void WebPageInspectorController::setIndicating(bool indicating)
 {
@@ -148,6 +243,55 @@ void WebPageInspectorController::setIndicating(bool indicating)
 }
 #endif
 
+void WebPageInspectorController::navigate(WebCore::ResourceRequest&& request, WebFrameProxy* frame, NavigationHandler&& completionHandler)
+{
+    auto navigation = m_page.loadRequestForInspector(WTFMove(request), frame);
+    if (!navigation) {
+        completionHandler("Failed to navigate"_s, 0);
+        return;
+    }
+
+    m_pendingNavigations.set(navigation->navigationID(), WTFMove(completionHandler));
+}
+
+void WebPageInspectorController::didReceivePolicyDecision(WebCore::PolicyAction action, uint64_t navigationID)
+{
+    if (!m_frontendRouter->hasFrontends())
+        return;
+
+    if (!navigationID)
+        return;
+
+    auto completionHandler = m_pendingNavigations.take(navigationID);
+    if (!completionHandler)
+        return;
+
+    if (action == WebCore::PolicyAction::Ignore)
+        completionHandler("Navigation cancelled"_s, 0);
+    else
+        completionHandler(String(), navigationID);
+}
+
+void WebPageInspectorController::didDestroyNavigation(uint64_t navigationID)
+{
+    if (!m_frontendRouter->hasFrontends())
+        return;
+
+    auto completionHandler = m_pendingNavigations.take(navigationID);
+    if (!completionHandler)
+        return;
+
+    // Inspector initiated navigation is destroyed before policy check only when it
+    // becomes a fragment navigation (which always reuses current navigation).
+    completionHandler(String(), 0);
+}
+
+void WebPageInspectorController::didFailProvisionalLoadForFrame(uint64_t navigationID, const WebCore::ResourceError& error)
+{
+    if (s_observer)
+        s_observer->didFailProvisionalLoad(m_page, navigationID, error.localizedDescription());
+}
+
 void WebPageInspectorController::createInspectorTarget(const String& targetId, Inspector::InspectorTargetType type)
 {
     addTarget(InspectorTargetProxy::create(m_page, targetId, type));
@@ -167,6 +311,33 @@ void WebPageInspectorController::sendMessageToInspectorFrontend(const String& ta
     m_targetAgent->sendMessageFromTargetToFrontend(targetId, message);
 }
 
+void WebPageInspectorController::setPauseOnStart(bool shouldPause)
+{
+    ASSERT(m_frontendRouter->hasFrontends());
+    String errorString;
+    m_targetAgent->setPauseOnStart(errorString, shouldPause);
+}
+
+bool WebPageInspectorController::shouldPauseLoading() const
+{
+    if (!m_frontendRouter->hasFrontends())
+        return false;
+
+    if (!m_page.isPageOpenedByDOMShowingInitialEmptyDocument())
+        return false;
+
+    auto* target = m_targets.get(WebPageInspectorTarget::toTargetID(m_page.webPageID()));
+    ASSERT(target);
+    return target->isPaused();
+}
+
+void WebPageInspectorController::setContinueLoadingCallback(WTF::Function<void()>&& callback)
+{
+    auto* target = m_targets.get(WebPageInspectorTarget::toTargetID(m_page.webPageID()));
+    ASSERT(target);
+    target->setResumeCallback(WTFMove(callback));
+}
+
 bool WebPageInspectorController::shouldPauseLoading(const ProvisionalPageProxy& provisionalPage) const
 {
     if (!m_frontendRouter->hasFrontends())
@@ -186,7 +357,7 @@ void WebPageInspectorController::setContinueLoadingCallback(const ProvisionalPag
 
 void WebPageInspectorController::didCreateProvisionalPage(ProvisionalPageProxy& provisionalPage)
 {
-    addTarget(InspectorTargetProxy::create(provisionalPage, getTargetID(provisionalPage), Inspector::InspectorTargetType::Page));
+    addTarget(InspectorTargetProxy::create(provisionalPage, getTargetID(provisionalPage)));
 }
 
 void WebPageInspectorController::willDestroyProvisionalPage(const ProvisionalPageProxy& provisionalPage)
@@ -218,4 +389,20 @@ void WebPageInspectorController::addTarget(std::unique_ptr<InspectorTargetProxy>
     m_targets.set(target->identifier(), WTFMove(target));
 }
 
+void WebPageInspectorController::adjustPageSettings()
+{
+    // Set this to true as otherwise updating any preferences will override its
+    // value in the Web Process to false (and InspectorController sets it locally
+    // to true when frontend is connected).
+    m_page.preferences().setDeveloperExtrasEnabled(true);
+
+    // Navigation to cached pages doesn't fire some of the events (e.g. execution context created)
+    // that inspector depends on. So we disable the cache when front-end connects.
+    m_page.preferences().setUsesBackForwardCache(false);
+
+    // Enable popup debugging.
+    // TODO: allow to set preferences over the inspector protocol or find a better place for this.
+    m_page.preferences().setJavaScriptCanOpenWindowsAutomatically(true);
+}
+
 } // namespace WebKit
diff --git a/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.h b/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.h
index 78caedf0c0ce83675569502d150fcc44e5f9868c..42070f8b1969caa0d00863279fcefe0125452734 100644
--- a/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.h
+++ b/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.h
@@ -26,6 +26,7 @@
 #pragma once
 
 #include "InspectorTargetProxy.h"
+#include "ProcessTerminationReason.h"
 #include <JavaScriptCore/InspectorAgentRegistry.h>
 #include <JavaScriptCore/InspectorTargetAgent.h>
 #include <WebCore/PageIdentifier.h>
@@ -37,10 +38,31 @@ namespace Inspector {
 class BackendDispatcher;
 class FrontendChannel;
 class FrontendRouter;
+class InspectorTarget;
+}
+
+namespace WebCore {
+class ResourceError;
+class ResourceRequest;
+enum class PolicyAction : uint8_t;
 }
 
 namespace WebKit {
 
+class WebFrameProxy;
+class WebPageInspectorEmulationAgent;
+class WebPageInspectorInputAgent;
+
+class WebPageInspectorControllerObserver {
+public:
+    virtual void didCreateInspectorController(WebPageProxy&) = 0;
+    virtual void willDestroyInspectorController(WebPageProxy&) = 0;
+    virtual void didFailProvisionalLoad(WebPageProxy&, uint64_t navigationID, const String& error) = 0;
+
+protected:
+    virtual ~WebPageInspectorControllerObserver() = default;
+};
+
 class WebPageInspectorController {
     WTF_MAKE_NONCOPYABLE(WebPageInspectorController);
     WTF_MAKE_FAST_ALLOCATED;
@@ -48,7 +70,17 @@ public:
     WebPageInspectorController(WebPageProxy&);
 
     void init();
+    void didFinishAttachingToWebProcess();
+
+    static void setObserver(WebPageInspectorControllerObserver*);
+
     void pageClosed();
+    bool pageCrashed(ProcessTerminationReason);
+
+    void didShowPage();
+
+    void didProcessAllPendingKeyboardEvents();
+    void didProcessAllPendingMouseEvents();
 
     bool hasLocalFrontend() const;
 
@@ -57,15 +89,28 @@ public:
     void disconnectAllFrontends();
 
     void dispatchMessageFromFrontend(const String& message);
+    bool dispatchMessageToTargetBackend(const String&);
 
 #if ENABLE(REMOTE_INSPECTOR)
     void setIndicating(bool);
 #endif
 
+    using NavigationHandler = Function<void(const String&, uint64_t)>;
+    void navigate(WebCore::ResourceRequest&&, WebFrameProxy*, NavigationHandler&&);
+    void didReceivePolicyDecision(WebCore::PolicyAction action, uint64_t navigationID);
+    void didDestroyNavigation(uint64_t navigationID);
+
+    void didFailProvisionalLoadForFrame(uint64_t navigationID, const WebCore::ResourceError& error);
+
     void createInspectorTarget(const String& targetId, Inspector::InspectorTargetType);
     void destroyInspectorTarget(const String& targetId);
     void sendMessageToInspectorFrontend(const String& targetId, const String& message);
 
+    void setPauseOnStart(bool);
+
+    bool shouldPauseLoading() const;
+    void setContinueLoadingCallback(WTF::Function<void()>&&);
+
     bool shouldPauseLoading(const ProvisionalPageProxy&) const;
     void setContinueLoadingCallback(const ProvisionalPageProxy&, WTF::Function<void()>&&);
 
@@ -75,13 +120,19 @@ public:
 
 private:
     void addTarget(std::unique_ptr<InspectorTargetProxy>&&);
+    void adjustPageSettings();
 
     WebPageProxy& m_page;
     Ref<Inspector::FrontendRouter> m_frontendRouter;
     Ref<Inspector::BackendDispatcher> m_backendDispatcher;
     Inspector::AgentRegistry m_agents;
-    Inspector::InspectorTargetAgent* m_targetAgent;
+    Inspector::InspectorTargetAgent* m_targetAgent { nullptr };
+    WebPageInspectorEmulationAgent* m_emulationAgent { nullptr };
+    WebPageInspectorInputAgent* m_inputAgent { nullptr };
     HashMap<String, std::unique_ptr<InspectorTargetProxy>> m_targets;
+    HashMap<uint64_t, NavigationHandler> m_pendingNavigations;
+
+    static WebPageInspectorControllerObserver* s_observer;
 };
 
 } // namespace WebKit
diff --git a/Source/WebKit/UIProcess/InspectorBrowserAgent.cpp b/Source/WebKit/UIProcess/InspectorBrowserAgent.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..7992dc1f6542ce5e219acda63d4ebd678c2ebcda
--- /dev/null
+++ b/Source/WebKit/UIProcess/InspectorBrowserAgent.cpp
@@ -0,0 +1,588 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "InspectorBrowserAgent.h"
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "APIPageConfiguration.h"
+#include "InspectorBrowserAgentClient.h"
+#include "InspectorTargetProxy.h"
+#include "NetworkProcessMessages.h"
+#include "NetworkProcessProxy.h"
+#include "WebGeolocationManagerProxy.h"
+#include "WebGeolocationPosition.h"
+#include "WebPageInspectorController.h"
+#include "WebPageInspectorTarget.h"
+#include "WebPageProxy.h"
+#include "WebProcessPool.h"
+#include "WebProcessProxy.h"
+#include <WebCore/FrameIdentifier.h>
+#include <WebCore/GeolocationPositionData.h>
+#include <WebCore/ProcessIdentifier.h>
+#include <WebCore/ResourceRequest.h>
+#include <JavaScriptCore/InspectorFrontendRouter.h>
+#include <pal/SessionID.h>
+#include <stdlib.h>
+#include <wtf/HashMap.h>
+#include <wtf/HexNumber.h>
+
+
+using namespace Inspector;
+
+namespace WebKit {
+
+namespace {
+
+Inspector::Protocol::Browser::CookieSameSitePolicy cookieSameSitePolicy(WebCore::Cookie::SameSitePolicy policy)
+{
+    switch (policy) {
+    case WebCore::Cookie::SameSitePolicy::None:
+        return Inspector::Protocol::Browser::CookieSameSitePolicy::None;
+    case WebCore::Cookie::SameSitePolicy::Lax:
+        return Inspector::Protocol::Browser::CookieSameSitePolicy::Lax;
+    case WebCore::Cookie::SameSitePolicy::Strict:
+        return Inspector::Protocol::Browser::CookieSameSitePolicy::Strict;
+    }
+    ASSERT_NOT_REACHED();
+    return Inspector::Protocol::Browser::CookieSameSitePolicy::None;
+}
+
+Ref<Inspector::Protocol::Browser::Cookie> buildObjectForCookie(const WebCore::Cookie& cookie)
+{
+    return Inspector::Protocol::Browser::Cookie::create()
+        .setName(cookie.name)
+        .setValue(cookie.value)
+        .setDomain(cookie.domain)
+        .setPath(cookie.path)
+        .setExpires(cookie.expires)
+        .setHttpOnly(cookie.httpOnly)
+        .setSecure(cookie.secure)
+        .setSession(cookie.session)
+        .setSameSite(cookieSameSitePolicy(cookie.sameSite))
+        .release();
+}
+
+Ref<Inspector::Protocol::Browser::PageProxyInfo> buildPageProxyInfo(const WebPageProxy& page) {
+    auto result = Inspector::Protocol::Browser::PageProxyInfo::create()
+        .setPageProxyId(InspectorBrowserAgent::toPageProxyIDProtocolString(page))
+        .setBrowserContextId(InspectorBrowserAgent::toBrowserContextIDProtocolString(page.sessionID()))
+        .release();
+    auto* opener = page.configuration().relatedPage();
+    if (opener)
+        result->setOpenerId(InspectorBrowserAgent::toPageProxyIDProtocolString(*opener));
+    return result;
+}
+
+}  // namespace
+
+Vector<WebPageProxy*> BrowserContext::pages() const {
+    Vector<WebPageProxy*> pages;
+    for (auto& process : processPool->processes()) {
+        for (auto* page : process->pages())
+            pages.append(page);
+    }
+    return pages;
+}
+
+class InspectorBrowserAgent::BrowserContextDeletion {
+    WTF_MAKE_NONCOPYABLE(BrowserContextDeletion);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    BrowserContextDeletion(const BrowserContext& context, size_t numberOfPages, Ref<DeleteContextCallback>&& callback)
+        : m_browserContext(context)
+        , m_numberOfPages(numberOfPages)
+        , m_callback(WTFMove(callback)) { }
+
+    void willDestroyPage(const WebPageProxy& page)
+    {
+        ASSERT(m_browserContext.dataStore->sessionID() == page.sessionID());
+        // Check if new pages have been created during the context destruction and
+        // close all of them if necessary.
+        if (m_numberOfPages == 1) {
+            Vector<WebPageProxy*> pages = m_browserContext.pages();
+            size_t numberOfPages = pages.size();
+            if (numberOfPages > 1) {
+                m_numberOfPages = numberOfPages;
+                for (auto* existingPage : pages) {
+                    if (existingPage != &page)
+                        existingPage->closePage();
+                }
+            }
+        }
+        --m_numberOfPages;
+        if (m_numberOfPages)
+            return;
+        m_callback->sendSuccess();
+    }
+
+    bool isFinished() const { return !m_numberOfPages; }
+
+private:
+    BrowserContext m_browserContext;
+    size_t m_numberOfPages;
+    Ref<DeleteContextCallback> m_callback;
+};
+
+
+InspectorBrowserAgent::InspectorBrowserAgent(Inspector::FrontendRouter& frontendRouter, Inspector::BackendDispatcher& backendDispatcher, InspectorBrowserAgentClient* client, PageProxyIDMap& pageProxyIDMap)
+    : InspectorAgentBase("Browser"_s)
+    , m_frontendDispatcher(makeUnique<BrowserFrontendDispatcher>(frontendRouter))
+    , m_backendDispatcher(BrowserBackendDispatcher::create(backendDispatcher, this))
+    , m_client(client)
+    , m_pageProxyIDMap(pageProxyIDMap)
+{
+}
+
+InspectorBrowserAgent::~InspectorBrowserAgent() = default;
+
+void InspectorBrowserAgent::didCreateWebPageProxy(const WebPageProxy& page)
+{
+    if (m_isConnected)
+        m_frontendDispatcher->pageProxyCreated(buildPageProxyInfo(page));
+}
+
+void InspectorBrowserAgent::willDestroyWebPageProxy(const WebPageProxy& page)
+{
+    if (!m_isConnected)
+        return;
+
+    m_frontendDispatcher->pageProxyDestroyed(toPageProxyIDProtocolString(page));
+
+    auto it = m_browserContextDeletions.find(page.sessionID());
+    if (it == m_browserContextDeletions.end())
+        return;
+
+    it->value->willDestroyPage(page);
+    if (it->value->isFinished())
+        m_browserContextDeletions.remove(it);
+}
+
+void InspectorBrowserAgent::didCreateFrontendAndBackend(FrontendRouter*, BackendDispatcher*)
+{
+    m_isConnected = true;
+}
+
+void InspectorBrowserAgent::didFailProvisionalLoad(WebPageProxy& page, uint64_t navigationID, const String& error)
+{
+    if (!m_isConnected)
+        return;
+
+    m_frontendDispatcher->provisionalLoadFailed(toPageProxyIDProtocolString(page), String::number(navigationID), error);
+}
+
+void InspectorBrowserAgent::willDestroyFrontendAndBackend(DisconnectReason)
+{
+    m_isConnected = false;
+    m_browserContextDeletions.clear();
+}
+
+void InspectorBrowserAgent::close(Ref<CloseCallback>&& callback)
+{
+    Vector<WebPageProxy*> pages;
+    for (auto& pool : WebProcessPool::allProcessPools()) {
+        for (auto& process : pool->processes()) {
+            for (auto* page : process->pages())
+                pages.append(page);
+        }
+    }
+    for (auto* page : pages)
+        page->closePage();
+
+    if (!WebProcessPool::allProcessPools().size()) {
+        m_client->closeBrowser();
+        callback->sendSuccess();
+        return;
+    }
+
+    WebProcessPool::allProcessPools().first()->syncLocalStorage([this, callback = WTFMove(callback)] () {
+        if (!callback->isActive())
+            return;
+
+        m_browserContexts.clear();
+        if (m_client == nullptr) {
+            callback->sendFailure("no platform delegate to close browser");
+        } else {
+            m_client->closeBrowser();
+            callback->sendSuccess();
+        }
+    });
+
+}
+
+void InspectorBrowserAgent::createContext(ErrorString& errorString, String* browserContextID)
+{
+    BrowserContext browserContext = m_client->createBrowserContext(errorString);
+    if (!errorString.isEmpty())
+        return;
+    browserContext.processPool->setPrimaryDataStore(*browserContext.dataStore);
+    browserContext.processPool->ensureNetworkProcess(browserContext.dataStore.get());
+    PAL::SessionID sessionID = browserContext.dataStore->sessionID();
+    *browserContextID = toBrowserContextIDProtocolString(sessionID);
+    m_browserContexts.set(*browserContextID, browserContext);
+}
+
+void InspectorBrowserAgent::deleteContext(const String& browserContextID, Ref<DeleteContextCallback>&& callback)
+{
+    String errorString;
+    BrowserContext browserContext = lookupBrowserContext(errorString, &browserContextID);
+    if (!errorString.isEmpty()) {
+        callback->sendFailure(errorString);
+        return;
+    }
+
+    Vector<WebPageProxy*> pages = browserContext.pages();
+    PAL::SessionID sessionID = browserContext.dataStore->sessionID();
+    m_browserContexts.remove(browserContextID);
+    if (pages.isEmpty()) {
+        callback->sendSuccess();
+    } else {
+        m_browserContextDeletions.set(sessionID, makeUnique<BrowserContextDeletion>(browserContext, pages.size(), WTFMove(callback)));
+        for (auto* page : pages)
+            page->closePage();
+    }
+    m_client->deleteBrowserContext(errorString, sessionID);
+}
+
+void InspectorBrowserAgent::createPage(ErrorString& errorString, const String* browserContextID, String* pageProxyID)
+{
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty())
+        return;
+    RefPtr<WebPageProxy> page = m_client->createPage(errorString, browserContext);
+    if (!page)
+        return;
+    page->setPermissionsForAutomation(m_permissions.get(browserContextID ? *browserContextID : ""));
+    *pageProxyID = toPageProxyIDProtocolString(*page);
+}
+
+WebFrameProxy* InspectorBrowserAgent::frameForID(const String& frameID, String& error)
+{
+    size_t dotPos = frameID.find(".");
+    if (dotPos == notFound) {
+        error = "Invalid frame id"_s;
+        return nullptr;
+    }
+
+    if (!frameID.isAllASCII()) {
+        error = "Invalid frame id"_s;
+        return nullptr;
+    }
+
+    String processIDString = frameID.left(dotPos);
+    uint64_t pid = strtoull(processIDString.ascii().data(), 0, 10);
+    auto processID = makeObjectIdentifier<WebCore::ProcessIdentifierType>(pid);
+    WebProcessProxy* process = WebProcessProxy::processForIdentifier(processID);
+    if (!process) {
+        error = "Cannot find web process for the frame id"_s;
+        return nullptr;
+    }
+
+    String frameIDString = frameID.substring(dotPos + 1);
+    uint64_t frameIDNumber = strtoull(frameIDString.ascii().data(), 0, 10);
+    auto frameIdentifier = makeObjectIdentifier<WebCore::FrameIdentifierType>(frameIDNumber);
+    WebFrameProxy* frame = process->webFrame(frameIdentifier);
+    if (!frame) {
+        error = "Cannot find web frame for the frame id"_s;
+        return nullptr;
+    }
+
+    return frame;
+}
+
+void InspectorBrowserAgent::navigate(const String& url, const String& pageProxyID, const String* frameID, const String* referrer, Ref<NavigateCallback>&& callback)
+{
+    WebPageProxy* page = m_pageProxyIDMap.findPageProxy(pageProxyID);
+    if (!page) {
+        callback->sendFailure("Cannot find page proxy with provided 'pageProxyId'"_s);
+        return;
+    }
+
+    WebCore::ResourceRequest resourceRequest { url };
+
+    if (referrer)
+        resourceRequest.setHTTPReferrer(*referrer);
+
+    if (!resourceRequest.url().isValid()) {
+        callback->sendFailure("Cannot navigate to invalid URL"_s);
+        return;
+    }
+
+    WebFrameProxy* frame = nullptr;
+    if (frameID) {
+        String error;
+        frame = frameForID(*frameID, error);
+        if (!frame) {
+            callback->sendFailure(error);
+            return;
+        }
+
+        if (frame->page() != page) {
+            callback->sendFailure("Frame with specified is not from the specified page"_s);
+            return;
+        }
+    }
+
+    page->inspectorController().navigate(WTFMove(resourceRequest), frame, [callback = WTFMove(callback)](const String& error, uint64_t navigationID) {
+        if (!error.isEmpty()) {
+            callback->sendFailure(error);
+            return;
+        }
+
+        Optional<String> navigationIDString;
+        if (navigationID)
+            navigationIDString = String::number(navigationID);
+        callback->sendSuccess(navigationIDString);
+    });
+}
+
+void InspectorBrowserAgent::setIgnoreCertificateErrors(Inspector::ErrorString& errorString, const String* browserContextID, bool ignore)
+{
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty())
+        return;
+    browserContext.processPool->setIgnoreTLSErrors(ignore);
+}
+
+void InspectorBrowserAgent::getAllCookies(const String* browserContextID, Ref<GetAllCookiesCallback>&& callback) {
+    String errorString;
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty()) {
+        callback->sendFailure(errorString);
+        return;
+    }
+
+    PAL::SessionID sessionID = browserContext.dataStore->sessionID();
+    NetworkProcessProxy* networkProcess = browserContext.processPool->networkProcess();
+    networkProcess->sendWithAsyncReply(Messages::NetworkProcess::GetAllCookies(sessionID),
+        [callback = WTFMove(callback)](Vector<WebCore::Cookie> allCookies) {
+            if (!callback->isActive())
+                return;
+            auto cookies = JSON::ArrayOf<Inspector::Protocol::Browser::Cookie>::create();
+            for (const auto& cookie : allCookies)
+                cookies->addItem(buildObjectForCookie(cookie));
+            callback->sendSuccess(WTFMove(cookies));
+        }, 0);
+}
+
+void InspectorBrowserAgent::setCookies(const String* browserContextID, const JSON::Array& in_cookies, Ref<SetCookiesCallback>&& callback) {
+    String errorString;
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty()) {
+        callback->sendFailure(errorString);
+        return;
+    }
+
+    NetworkProcessProxy* networkProcess = browserContext.processPool->networkProcess();
+    PAL::SessionID sessionID = browserContext.dataStore->sessionID();
+
+    Vector<WebCore::Cookie> cookies;
+    for (unsigned i = 0; i < in_cookies.length(); ++i) {
+        RefPtr<JSON::Value> item = in_cookies.get(i);
+        RefPtr<JSON::Object> obj;
+        if (!item->asObject(obj)) {
+            errorString = "Invalid cookie payload format"_s;
+            return;
+        }
+
+        WebCore::Cookie cookie;
+        if (!obj->getString("name", cookie.name) ||
+            !obj->getString("value", cookie.value) ||
+            !obj->getString("domain", cookie.domain) ||
+            !obj->getString("path", cookie.path)) {
+            errorString = "Invalid file payload format"_s;
+            return;
+        }
+
+        obj->getDouble("expires", cookie.expires);
+        obj->getBoolean("httpOnly", cookie.httpOnly);
+        obj->getBoolean("secure", cookie.secure);
+        obj->getBoolean("session", cookie.session);
+        String sameSite;
+        if (obj->getString("sameSite", sameSite)) {
+            if (sameSite == "None")
+                cookie.sameSite = WebCore::Cookie::SameSitePolicy::None;
+            if (sameSite == "Lax")
+                cookie.sameSite = WebCore::Cookie::SameSitePolicy::Lax;
+            if (sameSite == "Strict")
+                cookie.sameSite = WebCore::Cookie::SameSitePolicy::Strict;
+        }
+        cookies.append(WTFMove(cookie));
+    }
+
+    networkProcess->sendWithAsyncReply(Messages::NetworkProcess::SetCookies(sessionID, WTFMove(cookies)),
+        [callback = WTFMove(callback)](bool success) {
+            if (!callback->isActive())
+                return;
+
+            if (success)
+                callback->sendSuccess();
+            else
+                callback->sendFailure("Internal error: no network storage"_s);
+            callback->sendSuccess();
+        }, 0);
+}
+
+void InspectorBrowserAgent::deleteAllCookies(const String* browserContextID, Ref<DeleteAllCookiesCallback>&& callback) {
+    String errorString;
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty()) {
+        callback->sendFailure(errorString);
+        return;
+    }
+
+    NetworkProcessProxy* networkProcess = browserContext.processPool->networkProcess();
+    PAL::SessionID sessionID = browserContext.dataStore->sessionID();
+    networkProcess->sendWithAsyncReply(Messages::NetworkProcess::DeleteAllCookies(sessionID),
+        [callback = WTFMove(callback)](bool success) {
+            if (!callback->isActive())
+                return;
+            if (success)
+                callback->sendSuccess();
+            else
+                callback->sendFailure("Internal error: no network storage"_s);
+        }, 0);
+}
+
+void InspectorBrowserAgent::grantPermissions(Inspector::ErrorString& errorString, const String* browserContextID, const String& origin, const JSON::Array& values)
+{
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty())
+        return;
+    HashSet<String> set;
+    for (const auto& value : values) {
+        String name;
+        if (!value->asString(name)) {
+            errorString = "Permission must be a string"_s;
+            return;
+        }
+        set.add(name);
+    }
+    String key = browserContextID ? *browserContextID : "";
+    auto it = m_permissions.add(key, Permissions()).iterator;
+    it->value.set(origin, WTFMove(set));
+    Vector<WebPageProxy*> pages;
+    for (auto& process : browserContext.processPool->processes()) {
+        for (auto* page : process->pages())
+            page->setPermissionsForAutomation(it->value);
+    }
+}
+
+void InspectorBrowserAgent::resetPermissions(Inspector::ErrorString& errorString, const String* browserContextID)
+{
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty())
+        return;
+    m_permissions.clear();
+    for (auto& process : browserContext.processPool->processes()) {
+        for (auto* page : process->pages())
+            page->setPermissionsForAutomation(HashMap<String, HashSet<String>>());
+    }
+}
+
+void InspectorBrowserAgent::setLanguages(Inspector::ErrorString& errorString, const JSON::Array& languages, const String* browserContextID)
+{
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty())
+        return;
+
+    Vector<String> items;
+    for (const auto& value : languages) {
+        String language;
+        if (!value->asString(language)) {
+            errorString = "Language must be a string"_s;
+            return;
+        }
+        items.append(language);
+    }
+
+    browserContext.processPool->setLanguagesForAutomation(WTFMove(items));
+}
+
+void InspectorBrowserAgent::setGeolocationOverride(Inspector::ErrorString& errorString, const String* browserContextID, const JSON::Object* geolocation)
+{
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty())
+        return;
+    auto* geoManager = browserContext.processPool->supplement<WebGeolocationManagerProxy>();
+    if (!geoManager) {
+        errorString = "Internal error: geolocation manager is not available.";
+        return;
+    }
+    if (geolocation) {
+        double timestamp = 0;
+        double latitude = 0;
+        double longitude = 0;
+        double accuracy = 0;
+        if (!geolocation->getDouble("timestamp", timestamp) ||
+            !geolocation->getDouble("latitude", latitude) ||
+            !geolocation->getDouble("longitude", longitude) ||
+            !geolocation->getDouble("accuracy", accuracy)) {
+            errorString = "Invalid geolocation format"_s;
+            return;
+        }
+        auto position = WebGeolocationPosition::create(WebCore::GeolocationPositionData(timestamp, latitude, longitude, accuracy));
+        geoManager->providerDidChangePosition(&position.get());
+    } else {
+        geoManager->providerDidFailToDeterminePosition("Position unavailable"_s);
+    }
+}
+
+String InspectorBrowserAgent::toBrowserContextIDProtocolString(const PAL::SessionID& sessionID)
+{
+    StringBuilder builder;
+    builder.append(hex(sessionID.toUInt64(), 16));
+    return builder.toString();
+}
+
+String InspectorBrowserAgent::toPageProxyIDProtocolString(const WebPageProxy& page)
+{
+    return makeString(page.identifier().toUInt64());
+}
+
+BrowserContext InspectorBrowserAgent::lookupBrowserContext(ErrorString& errorString, const String* browserContextID)
+{
+    if (!browserContextID) {
+        BrowserContext context;
+        if (!WebProcessPool::allProcessPools().size()) {
+            errorString = "Browser started with no default context"_s;
+            return context;
+        }
+        auto* pool = WebProcessPool::allProcessPools().first();
+        context.processPool = pool;
+        context.dataStore = pool->websiteDataStore();
+        return context;
+    }
+
+    BrowserContext browserContext = m_browserContexts.get(*browserContextID);
+    if (!browserContext.processPool)
+        errorString = "Could not find browser context for given id"_s;
+    return browserContext;
+}
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/InspectorBrowserAgent.h b/Source/WebKit/UIProcess/InspectorBrowserAgent.h
new file mode 100644
index 0000000000000000000000000000000000000000..56ecacafe2d97971880f77913c40ec32393e1997
--- /dev/null
+++ b/Source/WebKit/UIProcess/InspectorBrowserAgent.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "InspectorBrowserAgentClient.h"
+#include <JavaScriptCore/InspectorAgentBase.h>
+#include <JavaScriptCore/InspectorBackendDispatchers.h>
+#include <wtf/HashMap.h>
+#include <pal/SessionID.h>
+#include <wtf/Forward.h>
+#include <wtf/Noncopyable.h>
+
+namespace Inspector {
+class BackendDispatcher;
+class BrowserFrontendDispatcher;
+class FrontendChannel;
+class FrontendRouter;
+}
+
+namespace PAL {
+class SessionID;
+}
+
+namespace WebKit {
+
+class NetworkProcess;
+class WebFrameProxy;
+class WebProcessPool;
+
+class PageProxyIDMap {
+public:
+    virtual WebPageProxy* findPageProxy(const String& pageProxyID) = 0;
+
+protected:
+    virtual ~PageProxyIDMap() = default;
+};
+
+class InspectorBrowserAgent final : public Inspector::InspectorAgentBase, public Inspector::BrowserBackendDispatcherHandler {
+    WTF_MAKE_NONCOPYABLE(InspectorBrowserAgent);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    InspectorBrowserAgent(Inspector::FrontendRouter&, Inspector::BackendDispatcher&, InspectorBrowserAgentClient*, PageProxyIDMap&);
+    ~InspectorBrowserAgent() override;
+
+    void didCreateWebPageProxy(const WebPageProxy&);
+    void willDestroyWebPageProxy(const WebPageProxy&);
+    void didFailProvisionalLoad(WebPageProxy&, uint64_t navigationID, const String& error);
+
+    // InspectorAgentBase
+    void didCreateFrontendAndBackend(Inspector::FrontendRouter*, Inspector::BackendDispatcher*) override;
+    void willDestroyFrontendAndBackend(Inspector::DisconnectReason) override;
+
+    // BrowserBackendDispatcherHandler
+    void close(Ref<CloseCallback>&&) override;
+    void createContext(Inspector::ErrorString&, String* browserContextID) override;
+    void deleteContext(const String& browserContextID, Ref<DeleteContextCallback>&& callback) override;
+    void createPage(Inspector::ErrorString&, const String* browserContextID, String* pageProxyID) override;
+    void navigate(const String& url, const String& pageProxyID, const String* frameId, const String* referrer, Ref<NavigateCallback>&&) override;
+    void setIgnoreCertificateErrors(Inspector::ErrorString&, const String* browserContextID, bool ignore) override;
+
+    void getAllCookies(const String* browserContextID, Ref<GetAllCookiesCallback>&&) override;
+    void setCookies(const String* browserContextID, const JSON::Array& in_cookies, Ref<SetCookiesCallback>&&) override;
+    void deleteAllCookies(const String* browserContextID, Ref<DeleteAllCookiesCallback>&&) override;
+
+    void grantPermissions(Inspector::ErrorString&, const String* browserContextID, const String& origin, const JSON::Array& permissions) override;
+    void resetPermissions(Inspector::ErrorString&, const String* browserContextID) override;
+    void setGeolocationOverride(Inspector::ErrorString&, const String* browserContextID, const JSON::Object* geolocation) override;
+    void setLanguages(Inspector::ErrorString&, const JSON::Array& languages, const String* browserContextID) override;
+
+    static String toBrowserContextIDProtocolString(const PAL::SessionID&);
+    static String toPageProxyIDProtocolString(const WebPageProxy&);
+
+private:
+    class BrowserContextDeletion;
+    BrowserContext lookupBrowserContext(Inspector::ErrorString&, const String* browserContextID);
+    WebFrameProxy* frameForID(const String& frameID, String& error);
+
+    std::unique_ptr<Inspector::BrowserFrontendDispatcher> m_frontendDispatcher;
+    Ref<Inspector::BrowserBackendDispatcher> m_backendDispatcher;
+    InspectorBrowserAgentClient* m_client;
+    PageProxyIDMap& m_pageProxyIDMap;
+    using Permissions = HashMap<String, HashSet<String>>;
+    HashMap<String, Permissions> m_permissions;
+    HashMap<String, BrowserContext> m_browserContexts;
+    HashMap<PAL::SessionID, std::unique_ptr<BrowserContextDeletion>> m_browserContextDeletions;
+    bool m_isConnected { false };
+};
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/InspectorBrowserAgentClient.h b/Source/WebKit/UIProcess/InspectorBrowserAgentClient.h
new file mode 100644
index 0000000000000000000000000000000000000000..199295c91249d0c400589249feaa2ed24ee35f19
--- /dev/null
+++ b/Source/WebKit/UIProcess/InspectorBrowserAgentClient.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include <pal/SessionID.h>
+#include <wtf/Forward.h>
+
+namespace WebKit {
+
+class WebsiteDataStore;
+class WebPageProxy;
+class WebProcessPool;
+
+struct BrowserContext {
+    Vector<WebPageProxy*> pages() const;
+    RefPtr<WebsiteDataStore> dataStore;
+    RefPtr<WebProcessPool> processPool;
+};
+
+class InspectorBrowserAgentClient {
+public:
+    virtual ~InspectorBrowserAgentClient() = default;
+    virtual RefPtr<WebKit::WebPageProxy> createPage(WTF::String& error, const BrowserContext& context) = 0;
+    virtual void closeBrowser() = 0;
+    virtual BrowserContext createBrowserContext(WTF::String& error) = 0;
+    virtual void deleteBrowserContext(WTF::String& error, PAL::SessionID) = 0;
+};
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/InspectorDialogAgent.cpp b/Source/WebKit/UIProcess/InspectorDialogAgent.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..ca5965f9d682c0821a40f0d1d43e5cbeda1353a5
--- /dev/null
+++ b/Source/WebKit/UIProcess/InspectorDialogAgent.cpp
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "InspectorDialogAgent.h"
+
+#include "APINavigation.h"
+#include "APIUIClient.h"
+#include "WebPageProxy.h"
+#include <JavaScriptCore/InspectorFrontendRouter.h>
+
+
+namespace WebKit {
+
+using namespace Inspector;
+
+InspectorDialogAgent::InspectorDialogAgent(Inspector::BackendDispatcher& backendDispatcher, Inspector::FrontendRouter& frontendRouter, WebPageProxy& page)
+    : InspectorAgentBase("Dialog"_s)
+    , m_frontendDispatcher(makeUnique<DialogFrontendDispatcher>(frontendRouter))
+    , m_backendDispatcher(DialogBackendDispatcher::create(backendDispatcher, this))
+    , m_page(page)
+{
+}
+
+InspectorDialogAgent::~InspectorDialogAgent()
+{
+    Inspector::ErrorString err;
+    disable(err);
+}
+
+void InspectorDialogAgent::didCreateFrontendAndBackend(Inspector::FrontendRouter*, Inspector::BackendDispatcher*)
+{
+}
+
+void InspectorDialogAgent::willDestroyFrontendAndBackend(Inspector::DisconnectReason)
+{
+}
+
+void InspectorDialogAgent::enable(Inspector::ErrorString& errorString)
+{
+    if (m_page.inspectorDialogAgent()) {
+        errorString = "Dialog domain is already enabled."_s;
+        return;
+    }
+    m_page.setInspectorDialogAgent(this);
+}
+
+void InspectorDialogAgent::disable(Inspector::ErrorString&)
+{
+    if (m_page.inspectorDialogAgent() != this)
+        return;
+    m_page.setInspectorDialogAgent(nullptr);
+}
+
+void InspectorDialogAgent::handleJavaScriptDialog(Inspector::ErrorString& errorString, bool accept, const String* value)
+{
+    m_page.uiClient().handleJavaScriptDialog(m_page, accept, value ? *value : String());
+}
+
+void InspectorDialogAgent::javascriptDialogOpening(const String& type, const String& message, const String* defaultValue) {
+    m_frontendDispatcher->javascriptDialogOpening(type, message, defaultValue);
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/InspectorDialogAgent.h b/Source/WebKit/UIProcess/InspectorDialogAgent.h
new file mode 100644
index 0000000000000000000000000000000000000000..f356c613945fd263889bc74166bef2b279ab4ca1
--- /dev/null
+++ b/Source/WebKit/UIProcess/InspectorDialogAgent.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "WebEvent.h"
+
+#include <JavaScriptCore/InspectorAgentBase.h>
+#include <JavaScriptCore/InspectorBackendDispatchers.h>
+#include <JavaScriptCore/InspectorFrontendDispatchers.h>
+
+#include <wtf/Forward.h>
+#include <wtf/Noncopyable.h>
+
+namespace Inspector {
+class FrontendChannel;
+class FrontendRouter;
+}
+
+namespace WebKit {
+
+class NativeWebKeyboardEvent;
+class WebPageProxy;
+
+class InspectorDialogAgent : public Inspector::InspectorAgentBase, public Inspector::DialogBackendDispatcherHandler {
+    WTF_MAKE_NONCOPYABLE(InspectorDialogAgent);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    InspectorDialogAgent(Inspector::BackendDispatcher& backendDispatcher, Inspector::FrontendRouter& frontendRouter, WebPageProxy& page);
+    ~InspectorDialogAgent() override;
+
+    void didCreateFrontendAndBackend(Inspector::FrontendRouter*, Inspector::BackendDispatcher*) override;
+    void willDestroyFrontendAndBackend(Inspector::DisconnectReason) override;
+
+    void enable(Inspector::ErrorString&) override;
+    void disable(Inspector::ErrorString&) override;
+    void handleJavaScriptDialog(Inspector::ErrorString& errorString, bool accept, const String* promptText) override;
+
+    void javascriptDialogOpening(const String& type, const String& message, const String* defaultValue = nullptr);
+
+private:
+    void platformHandleJavaScriptDialog(bool accept, const String* promptText);
+    std::unique_ptr<Inspector::DialogFrontendDispatcher> m_frontendDispatcher;
+    Ref<Inspector::DialogBackendDispatcher> m_backendDispatcher;
+    WebPageProxy& m_page;
+};
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/Launcher/win/ProcessLauncherWin.cpp b/Source/WebKit/UIProcess/Launcher/win/ProcessLauncherWin.cpp
index 8a871bf2916d5eab86becf5fde0faed79283d88c..a19a429c4d53edf81c3028c7053265e6c22c171a 100644
--- a/Source/WebKit/UIProcess/Launcher/win/ProcessLauncherWin.cpp
+++ b/Source/WebKit/UIProcess/Launcher/win/ProcessLauncherWin.cpp
@@ -92,8 +92,11 @@ void ProcessLauncher::launchProcess()
 
     STARTUPINFO startupInfo { };
     startupInfo.cb = sizeof(startupInfo);
-    startupInfo.dwFlags = STARTF_USESHOWWINDOW;
+    startupInfo.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
     startupInfo.wShowWindow = SW_HIDE;
+    startupInfo.hStdInput = ::GetStdHandle(STD_INPUT_HANDLE);
+    startupInfo.hStdOutput = ::GetStdHandle(STD_OUTPUT_HANDLE);
+    startupInfo.hStdError = ::GetStdHandle(STD_ERROR_HANDLE);
     PROCESS_INFORMATION processInformation { };
     BOOL result = ::CreateProcess(0, commandLine.data(), 0, 0, true, 0, 0, 0, &startupInfo, &processInformation);
 
diff --git a/Source/WebKit/UIProcess/RemoteInspectorPipe.cpp b/Source/WebKit/UIProcess/RemoteInspectorPipe.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..45d8dc48601548951dc5c5ecd68958dbd47c89db
--- /dev/null
+++ b/Source/WebKit/UIProcess/RemoteInspectorPipe.cpp
@@ -0,0 +1,220 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "RemoteInspectorPipe.h"
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "BrowserInspectorController.h"
+#include <JavaScriptCore/InspectorFrontendChannel.h>
+#include <wtf/MainThread.h>
+#include <wtf/RunLoop.h>
+#include <wtf/UniqueArray.h>
+#include <wtf/Vector.h>
+#include <wtf/WorkQueue.h>
+
+#if OS(UNIX)
+#include <stdio.h>
+#include <unistd.h>
+#endif
+
+#if PLATFORM(WIN)
+#include <io.h>
+#endif
+
+namespace WebKit {
+
+namespace {
+
+const int readFD = 3;
+const int writeFD = 4;
+
+const size_t kWritePacketSize = 1 << 16;
+
+#if PLATFORM(WIN)
+HANDLE readHandle;
+HANDLE writeHandle;
+#endif
+
+size_t ReadBytes(void* buffer, size_t size, bool exact_size)
+{
+    size_t bytesRead = 0;
+    while (bytesRead < size) {
+#if PLATFORM(WIN)
+        DWORD sizeRead = 0;
+        bool hadError = !ReadFile(readHandle, static_cast<char*>(buffer) + bytesRead,
+            size - bytesRead, &sizeRead, nullptr);
+#else
+        int sizeRead = read(readFD, static_cast<char*>(buffer) + bytesRead,
+            size - bytesRead);
+        if (sizeRead < 0 && errno == EINTR)
+            continue;
+        bool hadError = sizeRead <= 0;
+#endif
+        if (hadError) {
+            return 0;
+        }
+        bytesRead += sizeRead;
+        if (!exact_size)
+            break;
+    }
+    return bytesRead;
+}
+
+void WriteBytes(const char* bytes, size_t size)
+{
+    size_t totalWritten = 0;
+    while (totalWritten < size) {
+        size_t length = size - totalWritten;
+        if (length > kWritePacketSize)
+            length = kWritePacketSize;
+#if PLATFORM(WIN)
+        DWORD bytesWritten = 0;
+        bool hadError = !WriteFile(writeHandle, bytes + totalWritten, static_cast<DWORD>(length), &bytesWritten, nullptr);
+#else
+        int bytesWritten = write(writeFD, bytes + totalWritten, length);
+        if (bytesWritten < 0 && errno == EINTR)
+            continue;
+        bool hadError = bytesWritten <= 0;
+#endif
+        if (hadError)
+            return;
+        totalWritten += bytesWritten;
+    }
+}
+
+}  // namespace
+
+class RemoteInspectorPipe::RemoteFrontendChannel : public Inspector::FrontendChannel {
+    WTF_MAKE_FAST_ALLOCATED;
+
+public:
+    RemoteFrontendChannel()
+        : m_senderQueue(WorkQueue::create("Inspector pipe writer"))
+    {
+    }
+
+    ~RemoteFrontendChannel() override = default;
+
+    ConnectionType connectionType() const override
+    {
+        return ConnectionType::Remote;
+    }
+
+    void sendMessageToFrontend(const String& message) override
+    {
+        m_senderQueue->dispatch([message = message.isolatedCopy()]() {
+            WriteBytes(message.ascii().data(), message.length());
+            WriteBytes("\0", 1);
+        });
+    }
+
+private:
+    Ref<WorkQueue> m_senderQueue;
+};
+
+RemoteInspectorPipe::RemoteInspectorPipe(BrowserInspectorController& browserInspectorController)
+    : m_remoteFrontendChannel(makeUnique<RemoteFrontendChannel>())
+    , m_browserInspectorController(browserInspectorController)
+{
+    start();
+}
+
+RemoteInspectorPipe::~RemoteInspectorPipe()
+{
+    stop();
+}
+
+bool RemoteInspectorPipe::start()
+{
+    WTF::RunLoop::initializeMainRunLoop();
+    if (m_receiverThread)
+        return true;
+
+#if PLATFORM(WIN)
+    readHandle = reinterpret_cast<HANDLE>(_get_osfhandle(readFD));
+    writeHandle = reinterpret_cast<HANDLE>(_get_osfhandle(writeFD));
+#endif
+
+    m_browserInspectorController.connectFrontend(*m_remoteFrontendChannel);
+    m_terminated = false;
+    m_receiverThread = Thread::create("Inspector pipe reader", [this] {
+        workerRun();
+    });
+    return true;
+}
+
+void RemoteInspectorPipe::stop()
+{
+    if (!m_receiverThread)
+        return;
+
+    m_browserInspectorController.disconnectFrontend();
+
+    m_terminated = true;
+    m_receiverThread->waitForCompletion();
+    m_receiverThread = nullptr;
+}
+
+void RemoteInspectorPipe::workerRun()
+{
+    const size_t bufSize = 256 * 1024;
+    auto buffer = makeUniqueArray<char>(bufSize);
+    Vector<char> line;
+    while (!m_terminated) {
+        size_t size = ReadBytes(buffer.get(), bufSize, false);
+        if (!size)
+            break;
+        size_t start = 0;
+        size_t end = line.size();
+        line.append(buffer.get(), size);
+        while (true) {
+            for (; end < line.size(); ++end) {
+                if (line[end] == '\0')
+                    break;
+            }
+            if (end == line.size())
+                break;
+
+            if (end > start) {
+                String message = String::fromUTF8(line.data() + start, end - start);
+                RunLoop::main().dispatch([this, message] {
+                    if (!m_terminated)
+                        m_browserInspectorController.dispatchMessageFromFrontend(message);
+                });
+            }
+            ++end;
+            start = end;
+        }
+        if (start != 0 && start < line.size())
+            memmove(line.data(), line.data() + start, line.size() - start);
+        line.shrink(line.size() - start);
+    }
+}
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/RemoteInspectorPipe.h b/Source/WebKit/UIProcess/RemoteInspectorPipe.h
new file mode 100644
index 0000000000000000000000000000000000000000..b1307da8b9ee02d63ef98d276473d65a1d8c3556
--- /dev/null
+++ b/Source/WebKit/UIProcess/RemoteInspectorPipe.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include <wtf/Ref.h>
+#include <wtf/RefPtr.h>
+#include <wtf/Threading.h>
+
+namespace Inspector {
+class FrontendChannel;
+}
+
+namespace WebKit {
+
+class BrowserInspectorController;
+
+class RemoteInspectorPipe {
+    WTF_MAKE_NONCOPYABLE(RemoteInspectorPipe);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    explicit RemoteInspectorPipe(BrowserInspectorController&);
+    ~RemoteInspectorPipe();
+
+private:
+    class RemoteFrontendChannel;
+
+    bool start();
+    void stop();
+
+    void workerRun();
+
+    RefPtr<Thread> m_receiverThread;
+    std::atomic<bool> m_terminated { false };
+    std::unique_ptr<Inspector::FrontendChannel> m_remoteFrontendChannel;
+    BrowserInspectorController& m_browserInspectorController;
+};
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/WebAuthentication/AuthenticatorManager.cpp b/Source/WebKit/UIProcess/WebAuthentication/AuthenticatorManager.cpp
index 73626cc05027ae6e21b28143bc8009b92b1a75b4..52516a7f781c1a39376f9f78ab2f4749025bd34f 100644
--- a/Source/WebKit/UIProcess/WebAuthentication/AuthenticatorManager.cpp
+++ b/Source/WebKit/UIProcess/WebAuthentication/AuthenticatorManager.cpp
@@ -35,6 +35,7 @@
 #include "NfcService.h"
 #include "WebPageProxy.h"
 #include "WebPreferencesKeys.h"
+#include "WebProcessProxy.h"
 #include <WebCore/AuthenticatorAssertionResponse.h>
 #include <WebCore/AuthenticatorTransport.h>
 #include <WebCore/PublicKeyCredentialCreationOptions.h>
diff --git a/Source/WebKit/UIProcess/WebGeolocationManagerProxy.cpp b/Source/WebKit/UIProcess/WebGeolocationManagerProxy.cpp
index 04f3227cd55c992a42cd96a3f25d697aed7965a2..f0d36935f47bab03ea2ec50b705092068ecd3efa 100644
--- a/Source/WebKit/UIProcess/WebGeolocationManagerProxy.cpp
+++ b/Source/WebKit/UIProcess/WebGeolocationManagerProxy.cpp
@@ -128,7 +128,8 @@ void WebGeolocationManagerProxy::startUpdating(IPC::Connection& connection, WebP
     if (!wasUpdating) {
         m_provider->setEnableHighAccuracy(*this, isHighAccuracyEnabled());
         m_provider->startUpdating(*this);
-    } else if (m_lastPosition)
+    }
+    if (m_lastPosition)
         connection.send(Messages::WebGeolocationManager::DidChangePosition(m_lastPosition.value()), 0);
 }
 
diff --git a/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.cpp b/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..c863bd49011debe4b06cab64c113810809633777
--- /dev/null
+++ b/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.cpp
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "WebPageInspectorEmulationAgent.h"
+
+#include "APIPageConfiguration.h"
+#include "WebPageProxy.h"
+#include "WebPreferences.h"
+#include "PageClient.h"
+#include <JavaScriptCore/InspectorFrontendRouter.h>
+#include <WebCore/Credential.h>
+
+
+namespace WebKit {
+
+using namespace Inspector;
+
+WebPageInspectorEmulationAgent::WebPageInspectorEmulationAgent(BackendDispatcher& backendDispatcher, WebPageProxy& page)
+    : InspectorAgentBase("Emulation"_s)
+    , m_backendDispatcher(EmulationBackendDispatcher::create(backendDispatcher, this))
+    , m_page(page)
+{
+}
+
+WebPageInspectorEmulationAgent::~WebPageInspectorEmulationAgent()
+{
+}
+
+void WebPageInspectorEmulationAgent::didCreateFrontendAndBackend(FrontendRouter*, BackendDispatcher*)
+{
+}
+
+void WebPageInspectorEmulationAgent::willDestroyFrontendAndBackend(DisconnectReason)
+{
+   m_commandsToRunWhenShown.clear();
+}
+
+void WebPageInspectorEmulationAgent::setDeviceMetricsOverride(int width, int height, double deviceScaleFactor, bool fixedlayout, Ref<SetDeviceMetricsOverrideCallback>&& callback)
+{
+#if PLATFORM(GTK)
+    // On gtk, fixed layout doesn't work with compositing enabled
+    // FIXME: This turns off compositing forever, even if fixedLayout is disabled.
+    if (fixedlayout) {
+        auto copy = m_page.preferences().copy();
+        copy->setAcceleratedCompositingEnabled(false);
+        m_page.setPreferences(copy);
+    }
+#endif
+
+    m_page.setCustomDeviceScaleFactor(deviceScaleFactor);
+    m_page.setUseFixedLayout(fixedlayout);
+    if (!m_page.pageClient().isViewVisible() && m_page.configuration().relatedPage()) {
+        m_commandsToRunWhenShown.append([this, width, height, callback = WTFMove(callback)]() mutable {
+            setSize(width, height, WTFMove(callback));
+        });
+    } else {
+        setSize(width, height, WTFMove(callback));
+    }
+}
+
+void WebPageInspectorEmulationAgent::setSize(int width, int height, Ref<SetDeviceMetricsOverrideCallback>&& callback)
+{
+    platformSetSize(width, height, [callback = WTFMove(callback)](const String& error) {
+        if (error.isEmpty())
+            callback->sendSuccess();
+        else
+            callback->sendFailure(error);
+    });
+}
+
+void WebPageInspectorEmulationAgent::setJavaScriptEnabled(ErrorString&, bool enabled)
+{
+    auto copy = m_page.preferences().copy();
+    copy->setJavaScriptEnabled(enabled);
+    m_page.setPreferences(copy);
+}
+
+void WebPageInspectorEmulationAgent::setAuthCredentials(Inspector::ErrorString&, const String* username, const String* password)
+{
+    if (username && password)
+        m_page.setAuthCredentialsForAutomation(WebCore::Credential(*username, *password, CredentialPersistencePermanent));
+    else
+        m_page.setAuthCredentialsForAutomation(Optional<WebCore::Credential>());
+}
+
+void WebPageInspectorEmulationAgent::setActiveAndFocused(Inspector::ErrorString&, const bool* active)
+{
+    Optional<bool> value;
+    if (active)
+      value = *active;
+    m_page.setActiveForAutomation(value);
+}
+
+void WebPageInspectorEmulationAgent::didShowPage()
+{
+    for (auto& command : m_commandsToRunWhenShown)
+        command();
+    m_commandsToRunWhenShown.clear();
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.h b/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.h
new file mode 100644
index 0000000000000000000000000000000000000000..61969d8e4598f624df03beb56fc67375b9386edf
--- /dev/null
+++ b/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <JavaScriptCore/InspectorAgentBase.h>
+#include <JavaScriptCore/InspectorBackendDispatchers.h>
+
+#include <wtf/Forward.h>
+#include <wtf/Function.h>
+#include <wtf/Noncopyable.h>
+#include <wtf/Vector.h>
+
+namespace Inspector {
+class BackendDispatcher;
+class FrontendChannel;
+class FrontendRouter;
+}
+
+namespace WebKit {
+
+class WebPageProxy;
+
+class WebPageInspectorEmulationAgent : public Inspector::InspectorAgentBase, public Inspector::EmulationBackendDispatcherHandler {
+    WTF_MAKE_NONCOPYABLE(WebPageInspectorEmulationAgent);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    WebPageInspectorEmulationAgent(Inspector::BackendDispatcher& backendDispatcher, WebPageProxy& page);
+    ~WebPageInspectorEmulationAgent() override;
+
+    void didCreateFrontendAndBackend(Inspector::FrontendRouter*, Inspector::BackendDispatcher*) override;
+    void willDestroyFrontendAndBackend(Inspector::DisconnectReason) override;
+
+    void setDeviceMetricsOverride(int width, int height, double deviceScaleFactor, bool fixedlayout, Ref<SetDeviceMetricsOverrideCallback>&&) override;
+    void setJavaScriptEnabled(Inspector::ErrorString&, bool enabled) override;
+    void setAuthCredentials(Inspector::ErrorString&, const String*, const String*) override;
+    void setActiveAndFocused(Inspector::ErrorString&, const bool*) override;
+
+    void didShowPage();
+
+private:
+    void setSize(int width, int height, Ref<SetDeviceMetricsOverrideCallback>&& callback);
+    void platformSetSize(int width, int height, Function<void (const String& error)>&&);
+
+    Ref<Inspector::EmulationBackendDispatcher> m_backendDispatcher;
+    WebPageProxy& m_page;
+    Vector<Function<void()>> m_commandsToRunWhenShown;
+};
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/WebPageInspectorInputAgent.cpp b/Source/WebKit/UIProcess/WebPageInspectorInputAgent.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5043224bbd6378175c9ca7dce63fc5a233649878
--- /dev/null
+++ b/Source/WebKit/UIProcess/WebPageInspectorInputAgent.cpp
@@ -0,0 +1,253 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "WebPageInspectorInputAgent.h"
+
+#include "NativeWebKeyboardEvent.h"
+#include "NativeWebMouseEvent.h"
+#include "WebPageProxy.h"
+#include <wtf/MathExtras.h>
+
+namespace WebKit {
+
+using namespace Inspector;
+
+namespace {
+
+template<class T>
+class CallbackList {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    ~CallbackList()
+    {
+        for (const auto& callback : m_callbacks)
+            callback->sendFailure("Page closed");
+    }
+
+    void append(Ref<T>&& callback)
+    {
+        m_callbacks.append(WTFMove(callback));
+    }
+
+    void sendSuccess()
+    {
+        for (const auto& callback : m_callbacks)
+            callback->sendSuccess();
+        m_callbacks.clear();
+    }
+
+private:
+    Vector<Ref<T>> m_callbacks;
+};
+
+} // namespace
+
+class WebPageInspectorInputAgent::KeyboardCallbacks : public CallbackList<Inspector::InputBackendDispatcherHandler::DispatchKeyEventCallback> {
+};
+
+class WebPageInspectorInputAgent::MouseCallbacks : public CallbackList<Inspector::InputBackendDispatcherHandler::DispatchMouseEventCallback> {
+};
+
+WebPageInspectorInputAgent::WebPageInspectorInputAgent(Inspector::BackendDispatcher& backendDispatcher, WebPageProxy& page)
+    : InspectorAgentBase("Input"_s)
+    , m_backendDispatcher(InputBackendDispatcher::create(backendDispatcher, this))
+    , m_page(page)
+{
+}
+
+WebPageInspectorInputAgent::~WebPageInspectorInputAgent() = default;
+
+void WebPageInspectorInputAgent::didProcessAllPendingKeyboardEvents()
+{
+    m_keyboardCallbacks->sendSuccess();
+}
+
+void WebPageInspectorInputAgent::didProcessAllPendingMouseEvents()
+{
+    m_mouseCallbacks->sendSuccess();
+}
+
+void WebPageInspectorInputAgent::didCreateFrontendAndBackend(Inspector::FrontendRouter*, Inspector::BackendDispatcher*)
+{
+    m_keyboardCallbacks = makeUnique<KeyboardCallbacks>();
+    m_mouseCallbacks = makeUnique<MouseCallbacks>();
+}
+
+void WebPageInspectorInputAgent::willDestroyFrontendAndBackend(Inspector::DisconnectReason)
+{
+    m_keyboardCallbacks = nullptr;
+    m_mouseCallbacks = nullptr;
+}
+
+void WebPageInspectorInputAgent::dispatchKeyEvent(const String& type, const int* modifiers, const String* text, const String* unmodifiedText, const String* code, const String* key, const int* windowsVirtualKeyCode, const int* nativeVirtualKeyCode, const bool* autoRepeat, const bool* isKeypad, const bool* isSystemKey, const JSON::Array* commands, Ref<Inspector::InputBackendDispatcherHandler::DispatchKeyEventCallback>&& callback)
+{
+    WebKit::WebEvent::Type eventType;
+    if (type == "keyDown") {
+        eventType = WebKit::WebEvent::KeyDown;
+    } else if (type == "keyUp") {
+        eventType = WebKit::WebEvent::KeyUp;
+    } else {
+        callback->sendFailure("Unsupported event type.");
+        return;
+    }
+    OptionSet<WebEvent::Modifier> eventModifiers;
+    if (modifiers)
+        eventModifiers = eventModifiers.fromRaw(*modifiers);
+    String eventText;
+    if (text)
+        eventText = *text;
+    String eventUnmodifiedText;
+    if (unmodifiedText)
+        eventUnmodifiedText = *unmodifiedText;
+    String eventCode;
+    if (code)
+        eventCode = *code;
+    String eventKey;
+    if (key)
+        eventKey = *key;
+    int eventWindowsVirtualKeyCode = 0;
+    if (windowsVirtualKeyCode)
+        eventWindowsVirtualKeyCode = *windowsVirtualKeyCode;
+    int eventNativeVirtualKeyCode = 0;
+    if (nativeVirtualKeyCode)
+        eventNativeVirtualKeyCode = *nativeVirtualKeyCode;
+    Vector<String> eventCommands;
+    if (commands) {
+      for (const auto& value : *commands) {
+        String command;
+        if (!value->asString(command)) {
+          callback->sendFailure("Command must be string");
+          return;
+        }
+        eventCommands.append(command);
+      }
+    }
+
+    bool eventIsAutoRepeat = false;
+    if (autoRepeat)
+        eventIsAutoRepeat = *autoRepeat;
+    bool eventIsKeypad = false;
+    if (isKeypad)
+        eventIsKeypad = *isKeypad;
+    bool eventIsSystemKey = false;
+    if (isSystemKey)
+        eventIsSystemKey = *isSystemKey;
+    WallTime timestamp = WallTime::now();
+
+    m_keyboardCallbacks->append(WTFMove(callback));
+    platformDispatchKeyEvent(
+        eventType,
+        eventText,
+        eventUnmodifiedText,
+        eventKey,
+        eventCode,
+        eventWindowsVirtualKeyCode,
+        eventNativeVirtualKeyCode,
+        eventIsAutoRepeat,
+        eventIsKeypad,
+        eventIsSystemKey,
+        eventModifiers,
+        eventCommands,
+        timestamp);
+}
+
+void WebPageInspectorInputAgent::dispatchMouseEvent(const String& type, int x, int y, const int* modifiers, const String* button, const int* buttons, const int* clickCount, const int* deltaX, const int* deltaY, Ref<DispatchMouseEventCallback>&& callback)
+{
+    WebEvent::Type eventType = WebEvent::NoType;
+    if (type == "down")
+        eventType = WebEvent::MouseDown;
+    else if (type == "up")
+        eventType = WebEvent::MouseUp;
+    else if (type == "move")
+        eventType = WebEvent::MouseMove;
+    else {
+        callback->sendFailure("Unsupported event type");
+        return;
+    }
+
+    OptionSet<WebEvent::Modifier> eventModifiers;
+    if (modifiers)
+        eventModifiers = eventModifiers.fromRaw(*modifiers);
+
+    WebMouseEvent::Button eventButton = WebMouseEvent::NoButton;
+    if (button) {
+        if (*button == "left")
+            eventButton = WebMouseEvent::LeftButton;
+        else if (*button == "middle")
+            eventButton = WebMouseEvent::MiddleButton;
+        else if (*button == "right")
+            eventButton = WebMouseEvent::RightButton;
+        else if (*button == "none")
+            eventButton = WebMouseEvent::NoButton;
+        else {
+            callback->sendFailure("Unsupported eventButton");
+            return;
+        }
+    }
+
+    unsigned short eventButtons = 0;
+    if (buttons)
+        eventButtons = *buttons;
+
+    int eventClickCount = 0;
+    if (clickCount)
+        eventClickCount = *clickCount;
+    int eventDeltaX = 0;
+    if (deltaX)
+        eventDeltaX = *deltaX;
+    int eventDeltaY = 0;
+    if (deltaY)
+        eventDeltaY = *deltaY;
+    m_mouseCallbacks->append(WTFMove(callback));
+
+    // Convert css coordinates to view coordinates (dip).
+    double totalScale = m_page.pageScaleFactor() * m_page.viewScaleFactor();
+    x = clampToInteger(roundf(x * totalScale));
+    y = clampToInteger(roundf(y * totalScale));
+    eventDeltaX = clampToInteger(roundf(eventDeltaX * totalScale));
+    eventDeltaY = clampToInteger(roundf(eventDeltaY * totalScale));
+
+#if PLATFORM(MAC)
+    platformDispatchMouseEvent(type, x, y, modifiers, button, clickCount);
+#elif PLATFORM(GTK) || PLATFORM(WPE) || PLATFORM(WIN)
+    WallTime timestamp = WallTime::now();
+    NativeWebMouseEvent event(
+        eventType,
+        eventButton,
+        eventButtons,
+        {x, y},
+        WebCore::IntPoint(),
+        eventDeltaX,
+        eventDeltaY,
+        0,
+        eventClickCount,
+        eventModifiers,
+        timestamp);
+    m_page.handleMouseEvent(event);
+#endif
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/WebPageInspectorInputAgent.h b/Source/WebKit/UIProcess/WebPageInspectorInputAgent.h
new file mode 100644
index 0000000000000000000000000000000000000000..76290475097e756e3d932d22be4d8c797be4aa0c
--- /dev/null
+++ b/Source/WebKit/UIProcess/WebPageInspectorInputAgent.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "WebEvent.h"
+
+#include <JavaScriptCore/InspectorAgentBase.h>
+#include <JavaScriptCore/InspectorBackendDispatchers.h>
+
+#include <wtf/Forward.h>
+#include <wtf/Noncopyable.h>
+
+namespace Inspector {
+class BackendDispatcher;
+class FrontendChannel;
+class FrontendRouter;
+}
+
+namespace WebKit {
+
+class NativeWebKeyboardEvent;
+class WebPageProxy;
+
+class WebPageInspectorInputAgent : public Inspector::InspectorAgentBase, public Inspector::InputBackendDispatcherHandler {
+    WTF_MAKE_NONCOPYABLE(WebPageInspectorInputAgent);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    WebPageInspectorInputAgent(Inspector::BackendDispatcher& backendDispatcher, WebPageProxy& page);
+    ~WebPageInspectorInputAgent() override;
+
+    void didProcessAllPendingKeyboardEvents();
+    void didProcessAllPendingMouseEvents();
+
+    void didCreateFrontendAndBackend(Inspector::FrontendRouter*, Inspector::BackendDispatcher*) override;
+    void willDestroyFrontendAndBackend(Inspector::DisconnectReason) override;
+
+    // Protocol handler
+    void dispatchKeyEvent(const String& type, const int* modifiers, const String* text, const String* unmodifiedText, const String* code, const String* key, const int* windowsVirtualKeyCode, const int* nativeVirtualKeyCode, const bool* autoRepeat, const bool* isKeypad, const bool* isSystemKey, const JSON::Array*, Ref<DispatchKeyEventCallback>&& callback) override;
+    void dispatchMouseEvent(const String& type, int x, int y, const int* modifiers, const String* button, const int* buttons, const int* clickCount, const int* deltaX, const int* deltaY, Ref<DispatchMouseEventCallback>&& callback) override;
+
+private:
+    void platformDispatchKeyEvent(WebKeyboardEvent::Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<WebEvent::Modifier> modifiers, Vector<String>& commands, WallTime timestamp);
+#if PLATFORM(WPE)
+    void platformDispatchMouseEvent(WebMouseEvent::Type type, int x, int y, WebMouseEvent::Button button, OptionSet<WebEvent::Modifier> modifiers);
+#endif
+#if PLATFORM(MAC)
+    void platformDispatchMouseEvent(const String& type, int x, int y, const int* modifier, const String* button, const int* clickCount);
+#endif
+
+    Ref<Inspector::InputBackendDispatcher> m_backendDispatcher;
+    WebPageProxy& m_page;
+    // Keep track of currently active modifiers across multiple keystrokes.
+    // Most platforms do not track current modifiers from synthesized events.
+    unsigned m_currentModifiers { 0 };
+    class KeyboardCallbacks;
+    std::unique_ptr<KeyboardCallbacks> m_keyboardCallbacks;
+    class MouseCallbacks;
+    std::unique_ptr<MouseCallbacks> m_mouseCallbacks;
+};
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/WebPageProxy.cpp b/Source/WebKit/UIProcess/WebPageProxy.cpp
index f971f96f4df83ebf505b2ddc4ae27e6ca7d5cc75..7478490cc0a8234569b01ae578a68cff982aa457 100644
--- a/Source/WebKit/UIProcess/WebPageProxy.cpp
+++ b/Source/WebKit/UIProcess/WebPageProxy.cpp
@@ -917,6 +917,7 @@ void WebPageProxy::finishAttachingToWebProcess(ProcessLaunchReason reason)
     m_pageLoadState.didSwapWebProcesses();
     if (reason != ProcessLaunchReason::InitialProcess)
         m_drawingArea->waitForBackingStoreUpdateOnNextPaint();
+    m_inspectorController->didFinishAttachingToWebProcess();
 }
 
 void WebPageProxy::didAttachToRunningProcess()
@@ -1256,6 +1257,21 @@ WebProcessProxy& WebPageProxy::ensureRunningProcess()
     return m_process;
 }
 
+RefPtr<API::Navigation> WebPageProxy::loadRequestForInspector(WebCore::ResourceRequest&& request, WebFrameProxy* frame)
+{
+    if (!frame || frame == mainFrame())
+        return loadRequest(WTFMove(request), WebCore::ShouldOpenExternalURLsPolicy::ShouldNotAllow);
+
+    auto navigation = m_navigationState->createLoadRequestNavigation(ResourceRequest(request), m_backForwardList->currentItem());
+    LoadParameters loadParameters;
+    loadParameters.navigationID = navigation->navigationID();
+    loadParameters.request = WTFMove(request);
+    loadParameters.shouldOpenExternalURLsPolicy = WebCore::ShouldOpenExternalURLsPolicy::ShouldNotAllow;
+    loadParameters.shouldTreatAsContinuingLoad = false;
+    m_process->send(Messages::WebPage::LoadRequestInFrameForInspector(loadParameters, frame->frameID()),  m_webPageID);
+    return navigation;
+}
+
 RefPtr<API::Navigation> WebPageProxy::loadRequest(ResourceRequest&& request, ShouldOpenExternalURLsPolicy shouldOpenExternalURLsPolicy, API::Object* userData)
 {
     if (m_isClosed)
@@ -1708,6 +1724,31 @@ void WebPageProxy::setControlledByAutomation(bool controlled)
     m_process->processPool().sendToNetworkingProcess(Messages::NetworkProcess::SetSessionIsControlledByAutomation(m_websiteDataStore->sessionID(), m_controlledByAutomation));
 }
 
+void WebPageProxy::setAuthCredentialsForAutomation(Optional<WebCore::Credential>&& credentials)
+{
+    m_credentialsForAutomation = WTFMove(credentials);
+}
+
+void WebPageProxy::setPermissionsForAutomation(const HashMap<String, HashSet<String>>& permissions)
+{
+    m_permissionsForAutomation = permissions;
+}
+
+void WebPageProxy::setActiveForAutomation(Optional<bool> active) {
+    m_activeForAutomation = active;
+    OptionSet<ActivityState::Flag> state;
+    state.add(ActivityState::IsFocused);
+    state.add(ActivityState::WindowIsActive);
+    state.add(ActivityState::IsVisible);
+    state.add(ActivityState::IsVisibleOrOccluded);
+    activityStateDidChange(state);
+}
+
+void WebPageProxy::logToStderr(const String& str)
+{
+    fprintf(stderr, "RENDERER: %s\n", str.utf8().data());
+}
+
 void WebPageProxy::createInspectorTarget(const String& targetId, Inspector::InspectorTargetType type)
 {
     MESSAGE_CHECK(m_process, !targetId.isEmpty());
@@ -1850,6 +1891,25 @@ void WebPageProxy::updateActivityState(OptionSet<ActivityState::Flag> flagsToUpd
 {
     bool wasVisible = isViewVisible();
     m_activityState.remove(flagsToUpdate);
+
+
+    if (m_activeForAutomation) {
+        if (*m_activeForAutomation) {
+            if (flagsToUpdate & ActivityState::IsFocused)
+                m_activityState.add(ActivityState::IsFocused);
+            if (flagsToUpdate & ActivityState::WindowIsActive)
+                m_activityState.add(ActivityState::WindowIsActive);
+            if (flagsToUpdate & ActivityState::IsVisible)
+                m_activityState.add(ActivityState::IsVisible);
+            if (flagsToUpdate & ActivityState::IsVisibleOrOccluded)
+                m_activityState.add(ActivityState::IsVisibleOrOccluded);
+        }
+        flagsToUpdate.remove(ActivityState::IsFocused);
+        flagsToUpdate.remove(ActivityState::WindowIsActive);
+        flagsToUpdate.remove(ActivityState::IsVisible);
+        flagsToUpdate.remove(ActivityState::IsVisibleOrOccluded);
+    }
+
     if (flagsToUpdate & ActivityState::IsFocused && pageClient().isViewFocused())
         m_activityState.add(ActivityState::IsFocused);
     if (flagsToUpdate & ActivityState::WindowIsActive && pageClient().isViewWindowActive())
@@ -2795,7 +2855,7 @@ static TrackingType mergeTrackingTypes(TrackingType a, TrackingType b)
 
 void WebPageProxy::updateTouchEventTracking(const WebTouchEvent& touchStartEvent)
 {
-#if ENABLE(ASYNC_SCROLLING) && PLATFORM(COCOA)
+#if ENABLE(ASYNC_SCROLLING) && PLATFORM(IOS_FAMILY)
     const EventNames& names = eventNames();
     for (auto& touchPoint : touchStartEvent.touchPoints()) {
         IntPoint location = touchPoint.location();
@@ -2828,7 +2888,7 @@ void WebPageProxy::updateTouchEventTracking(const WebTouchEvent& touchStartEvent
     m_touchAndPointerEventTracking.touchStartTracking = TrackingType::Synchronous;
     m_touchAndPointerEventTracking.touchMoveTracking = TrackingType::Synchronous;
     m_touchAndPointerEventTracking.touchEndTracking = TrackingType::Synchronous;
-#endif // ENABLE(ASYNC_SCROLLING)
+#endif // ENABLE(ASYNC_SCROLLING) && PLATFORM(IOS_FAMILY)
 }
 
 TrackingType WebPageProxy::touchEventTrackingType(const WebTouchEvent& touchStartEvent) const
@@ -3191,6 +3251,7 @@ void WebPageProxy::receivedNavigationPolicyDecision(PolicyAction policyAction, A
 
 void WebPageProxy::receivedPolicyDecision(PolicyAction action, API::Navigation* navigation, Optional<WebsitePoliciesData>&& websitePolicies, Ref<PolicyDecisionSender>&& sender, WillContinueLoadInNewProcess willContinueLoadInNewProcess)
 {
+    m_inspectorController->didReceivePolicyDecision(action, navigation ? navigation->navigationID() : 0);
     if (!hasRunningProcess()) {
         sender->send(PolicyDecision { sender->identifier(), isNavigatingToAppBoundDomain(), PolicyAction::Ignore, 0, DownloadID(), WTF::nullopt });
         return;
@@ -3875,6 +3936,11 @@ void WebPageProxy::pageScaleFactorDidChange(double scaleFactor)
     m_pageScaleFactor = scaleFactor;
 }
 
+void WebPageProxy::viewScaleFactorDidChange(double scaleFactor)
+{
+    m_viewScaleFactor = scaleFactor;
+}
+
 void WebPageProxy::pluginScaleFactorDidChange(double pluginScaleFactor)
 {
     m_pluginScaleFactor = pluginScaleFactor;
@@ -4296,6 +4362,7 @@ void WebPageProxy::didDestroyNavigation(uint64_t navigationID)
 
     // FIXME: Message check the navigationID.
     m_navigationState->didDestroyNavigation(navigationID);
+    m_inspectorController->didDestroyNavigation(navigationID);
 }
 
 void WebPageProxy::didStartProvisionalLoadForFrame(FrameIdentifier frameID, uint64_t navigationID, URL&& url, URL&& unreachableURL, const UserData& userData)
@@ -4519,6 +4586,8 @@ void WebPageProxy::didFailProvisionalLoadForFrameShared(Ref<WebProcessProxy>&& p
 
     m_failingProvisionalLoadURL = { };
 
+    m_inspectorController->didFailProvisionalLoadForFrame(navigationID, error);
+
     // If the provisional page's load fails then we destroy the provisional page.
     if (m_provisionalPage && m_provisionalPage->mainFrame() == frame && willContinueLoading == WillContinueLoading::No)
         m_provisionalPage = nullptr;
@@ -4961,8 +5030,16 @@ void WebPageProxy::decidePolicyForNavigationActionAsync(FrameIdentifier frameID,
     NavigationActionData&& navigationActionData, FrameInfoData&& frameInfoData, Optional<WebPageProxyIdentifier> originatingPageID, const WebCore::ResourceRequest& originalRequest, WebCore::ResourceRequest&& request,
     IPC::FormDataReference&& requestBody, WebCore::ResourceResponse&& redirectResponse, const UserData& userData, uint64_t listenerID)
 {
-    decidePolicyForNavigationActionAsyncShared(m_process.copyRef(), m_webPageID, frameID, WTFMove(frameSecurityOrigin), identifier, navigationID, WTFMove(navigationActionData),
-        WTFMove(frameInfoData), originatingPageID, originalRequest, WTFMove(request), WTFMove(requestBody), WTFMove(redirectResponse), userData, listenerID);
+    if (m_inspectorController->shouldPauseLoading())
+        m_inspectorController->setContinueLoadingCallback([this, protectedThis = makeRef(*this), frameID, frameSecurityOrigin = WTFMove(frameSecurityOrigin), identifier, navigationID, navigationActionData = WTFMove(navigationActionData),
+                frameInfoData = WTFMove(frameInfoData), originatingPageID, originalRequest, request = WTFMove(request), requestBody = WTFMove(requestBody), redirectResponse = WTFMove(redirectResponse), userData, listenerID] () mutable {
+            decidePolicyForNavigationActionAsyncShared(m_process.copyRef(), m_webPageID, frameID, WTFMove(frameSecurityOrigin), identifier, navigationID, WTFMove(navigationActionData),
+                WTFMove(frameInfoData), originatingPageID, originalRequest, WTFMove(request), WTFMove(requestBody), WTFMove(redirectResponse), userData, listenerID);
+        });
+    else {
+        decidePolicyForNavigationActionAsyncShared(m_process.copyRef(), m_webPageID, frameID, WTFMove(frameSecurityOrigin), identifier, navigationID, WTFMove(navigationActionData),
+            WTFMove(frameInfoData), originatingPageID, originalRequest, WTFMove(request), WTFMove(requestBody), WTFMove(redirectResponse), userData, listenerID);
+    }
 }
 
 void WebPageProxy::decidePolicyForNavigationActionAsyncShared(Ref<WebProcessProxy>&& process, PageIdentifier webPageID, FrameIdentifier frameID, WebCore::SecurityOriginData&& frameSecurityOrigin,
@@ -5480,6 +5557,7 @@ void WebPageProxy::createNewPage(FrameInfoData&& originatingFrameInfoData, Optio
 void WebPageProxy::showPage()
 {
     m_uiClient->showPage(this);
+    m_inspectorController->didShowPage();
 }
 
 void WebPageProxy::exitFullscreenImmediately()
@@ -5536,6 +5614,8 @@ void WebPageProxy::runJavaScriptAlert(FrameIdentifier frameID, SecurityOriginDat
         if (auto* automationSession = process().processPool().automationSession())
             automationSession->willShowJavaScriptDialog(*this);
     }
+    if (m_inspectorDialogAgent)
+        m_inspectorDialogAgent->javascriptDialogOpening("alert"_s, message);
     m_uiClient->runJavaScriptAlert(*this, message, frame, WTFMove(securityOrigin), WTFMove(reply));
 }
 
@@ -5555,6 +5635,8 @@ void WebPageProxy::runJavaScriptConfirm(FrameIdentifier frameID, SecurityOriginD
         if (auto* automationSession = process().processPool().automationSession())
             automationSession->willShowJavaScriptDialog(*this);
     }
+    if (m_inspectorDialogAgent)
+        m_inspectorDialogAgent->javascriptDialogOpening("confirm"_s, message);
 
     m_uiClient->runJavaScriptConfirm(*this, message, frame, WTFMove(securityOrigin), WTFMove(reply));
 }
@@ -5574,6 +5656,8 @@ void WebPageProxy::runJavaScriptPrompt(FrameIdentifier frameID, SecurityOriginDa
         if (auto* automationSession = process().processPool().automationSession())
             automationSession->willShowJavaScriptDialog(*this);
     }
+    if (m_inspectorDialogAgent)
+        m_inspectorDialogAgent->javascriptDialogOpening("prompt"_s, message, &defaultValue);
 
     m_uiClient->runJavaScriptPrompt(*this, message, defaultValue, frame, WTFMove(securityOrigin), WTFMove(reply));
 }
@@ -5733,6 +5817,8 @@ void WebPageProxy::runBeforeUnloadConfirmPanel(FrameIdentifier frameID, Security
             return;
         }
     }
+    if (m_inspectorDialogAgent)
+        m_inspectorDialogAgent->javascriptDialogOpening("beforeunload"_s, message);
 
     // Since runBeforeUnloadConfirmPanel() can spin a nested run loop we need to turn off the responsiveness timer and the tryClose timer.
     m_process->stopResponsivenessTimer();
@@ -6795,6 +6881,7 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
             if (auto* automationSession = process().processPool().automationSession())
                 automationSession->mouseEventsFlushedForPage(*this);
             didFinishProcessingAllPendingMouseEvents();
+            m_inspectorController->didProcessAllPendingMouseEvents();
         }
 
         break;
@@ -6821,7 +6908,6 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
     case WebEvent::RawKeyDown:
     case WebEvent::Char: {
         LOG(KeyHandling, "WebPageProxy::didReceiveEvent: %s (queue empty %d)", webKeyboardEventTypeString(type), m_keyEventQueue.isEmpty());
-
         MESSAGE_CHECK(m_process, !m_keyEventQueue.isEmpty());
         NativeWebKeyboardEvent event = m_keyEventQueue.takeFirst();
 
@@ -6841,7 +6927,6 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
         // The call to doneWithKeyEvent may close this WebPage.
         // Protect against this being destroyed.
         Ref<WebPageProxy> protect(*this);
-
         pageClient().doneWithKeyEvent(event, handled);
         if (!handled)
             m_uiClient->didNotHandleKeyEvent(this, event);
@@ -6850,6 +6935,7 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
         if (!canProcessMoreKeyEvents) {
             if (auto* automationSession = process().processPool().automationSession())
                 automationSession->keyboardEventsFlushedForPage(*this);
+            m_inspectorController->didProcessAllPendingKeyboardEvents();
         }
         break;
     }
@@ -7307,8 +7393,10 @@ static bool shouldReloadAfterProcessTermination(ProcessTerminationReason reason)
 void WebPageProxy::dispatchProcessDidTerminate(ProcessTerminationReason reason)
 {
     RELEASE_LOG_IF_ALLOWED(Loading, "dispatchProcessDidTerminate: reason = %d", reason);
+    bool handledByClient = m_inspectorController->pageCrashed(reason);
+    if (handledByClient)
+        return;
 
-    bool handledByClient = false;
     if (m_loaderClient)
         handledByClient = reason != ProcessTerminationReason::RequestedByClient && m_loaderClient->processDidCrash(*this);
     else
@@ -7590,6 +7678,7 @@ void WebPageProxy::resetStateAfterProcessExited(ProcessTerminationReason termina
 
 WebPageCreationParameters WebPageProxy::creationParameters(WebProcessProxy& process, DrawingAreaProxy& drawingArea)
 {
+
     WebPageCreationParameters parameters;
 
     parameters.viewSize = pageClient().viewSize();
@@ -7720,6 +7809,8 @@ WebPageCreationParameters WebPageProxy::creationParameters(WebProcessProxy& proc
     parameters.shouldCaptureVideoInGPUProcess = m_process->processPool().configuration().shouldCaptureVideoInGPUProcess();
     parameters.shouldCaptureDisplayInUIProcess = m_process->processPool().configuration().shouldCaptureDisplayInUIProcess();
 
+    parameters.shouldPauseInInspectorWhenShown = m_inspectorController->shouldPauseLoading();
+
 #if PLATFORM(GTK)
     parameters.themeName = pageClient().themeName();
 #endif
@@ -7781,6 +7872,14 @@ void WebPageProxy::gamepadActivity(const Vector<GamepadData>& gamepadDatas, bool
 
 void WebPageProxy::didReceiveAuthenticationChallengeProxy(Ref<AuthenticationChallengeProxy>&& authenticationChallenge, NegotiatedLegacyTLS negotiatedLegacyTLS)
 {
+    if (m_credentialsForAutomation.hasValue()) {
+        if (m_credentialsForAutomation->isEmpty() || authenticationChallenge->core().previousFailureCount()) {
+            authenticationChallenge->listener().completeChallenge(AuthenticationChallengeDisposition::PerformDefaultHandling);
+            return;
+        }
+        authenticationChallenge->listener().completeChallenge(AuthenticationChallengeDisposition::UseCredential, *m_credentialsForAutomation);
+        return;
+    }
     if (negotiatedLegacyTLS == NegotiatedLegacyTLS::Yes) {
         m_navigationClient->shouldAllowLegacyTLS(*this, authenticationChallenge.get(), [this, protectedThis = makeRef(*this), authenticationChallenge = authenticationChallenge.copyRef()] (bool shouldAllowLegacyTLS) {
             if (shouldAllowLegacyTLS)
@@ -7863,7 +7962,8 @@ void WebPageProxy::requestGeolocationPermissionForFrame(uint64_t geolocationID,
     MESSAGE_CHECK(m_process, securityOriginData);
 
     // FIXME: Geolocation should probably be using toString() as its string representation instead of databaseIdentifier().
-    auto origin = API::SecurityOrigin::create(securityOriginData->securityOrigin());
+    auto securityOrigin = securityOriginData->securityOrigin();
+    auto origin = API::SecurityOrigin::create(securityOrigin);
     auto request = m_geolocationPermissionRequestManager.createRequest(geolocationID);
     Function<void(bool)> completionHandler = [request = WTFMove(request)](bool allowed) {
         if (allowed)
@@ -7871,6 +7971,11 @@ void WebPageProxy::requestGeolocationPermissionForFrame(uint64_t geolocationID,
         else
             request->deny();
     };
+    auto permissions = m_permissionsForAutomation.find(securityOrigin->toString());
+    if (permissions != m_permissionsForAutomation.end()) {
+        completionHandler(permissions->value.contains("geolocation"));
+        return;
+    }
 
     // FIXME: Once iOS migrates to the new WKUIDelegate SPI, clean this up
     // and make it one UIClient call that calls the completionHandler with false
diff --git a/Source/WebKit/UIProcess/WebPageProxy.h b/Source/WebKit/UIProcess/WebPageProxy.h
index b3154548a08b588dfb346261bc7de3dbb754f6cf..4fc0e0fb6e7805d04b86bca46d5098fc69fe32e4 100644
--- a/Source/WebKit/UIProcess/WebPageProxy.h
+++ b/Source/WebKit/UIProcess/WebPageProxy.h
@@ -36,6 +36,7 @@
 #include "FocusedElementInformation.h"
 #include "GeolocationPermissionRequestManagerProxy.h"
 #include "HiddenPageThrottlingAutoIncreasesCounter.h"
+#include "InspectorDialogAgent.h"
 #include "LayerTreeContext.h"
 #include "MessageSender.h"
 #include "NotificationPermissionRequestManagerProxy.h"
@@ -492,6 +493,8 @@ public:
     void setControlledByAutomation(bool);
 
     WebPageInspectorController& inspectorController() { return *m_inspectorController; }
+    InspectorDialogAgent* inspectorDialogAgent() { return m_inspectorDialogAgent; }
+    void setInspectorDialogAgent(InspectorDialogAgent * dialogAgent) { m_inspectorDialogAgent = dialogAgent; }
 
 #if PLATFORM(IOS_FAMILY)
     void showInspectorIndication();
@@ -558,6 +561,11 @@ public:
 
     void setPageLoadStateObserver(std::unique_ptr<PageLoadState::Observer>&&);
 
+    void setAuthCredentialsForAutomation(Optional<WebCore::Credential>&&);
+    void setPermissionsForAutomation(const HashMap<String, HashSet<String>>&);
+    void setActiveForAutomation(Optional<bool> active);
+    void logToStderr(const String& str);
+
     void initializeWebPage();
     void setDrawingArea(std::unique_ptr<DrawingAreaProxy>&&);
 
@@ -583,6 +591,7 @@ public:
     void closePage();
 
     void addPlatformLoadParameters(LoadParameters&);
+    RefPtr<API::Navigation> loadRequestForInspector(WebCore::ResourceRequest&&, WebFrameProxy*);
     RefPtr<API::Navigation> loadRequest(WebCore::ResourceRequest&&, WebCore::ShouldOpenExternalURLsPolicy = WebCore::ShouldOpenExternalURLsPolicy::ShouldAllowExternalSchemes, API::Object* userData = nullptr);
     RefPtr<API::Navigation> loadFile(const String& fileURL, const String& resourceDirectoryURL, API::Object* userData = nullptr);
     RefPtr<API::Navigation> loadData(const IPC::DataReference&, const String& MIMEType, const String& encoding, const String& baseURL, API::Object* userData = nullptr, WebCore::ShouldOpenExternalURLsPolicy = WebCore::ShouldOpenExternalURLsPolicy::ShouldNotAllow);
@@ -1059,6 +1068,7 @@ public:
 #endif
 
     void pageScaleFactorDidChange(double);
+    void viewScaleFactorDidChange(double);
     void pluginScaleFactorDidChange(double);
     void pluginZoomFactorDidChange(double);
 
@@ -2311,6 +2321,7 @@ private:
     String m_overrideContentSecurityPolicy;
 
     RefPtr<WebInspectorProxy> m_inspector;
+    InspectorDialogAgent* m_inspectorDialogAgent { nullptr };
 
 #if ENABLE(FULLSCREEN_API)
     std::unique_ptr<WebFullScreenManagerProxy> m_fullScreenManager;
@@ -2731,6 +2742,9 @@ private:
         RefPtr<API::Object> messageBody;
     };
     Vector<InjectedBundleMessage> m_pendingInjectedBundleMessages;
+    Optional<WebCore::Credential> m_credentialsForAutomation;
+    HashMap<String, HashSet<String>> m_permissionsForAutomation;
+    Optional<bool> m_activeForAutomation;
         
 #if PLATFORM(IOS_FAMILY) && ENABLE(DEVICE_ORIENTATION)
     std::unique_ptr<WebDeviceOrientationUpdateProviderProxy> m_webDeviceOrientationUpdateProviderProxy;
diff --git a/Source/WebKit/UIProcess/WebPageProxy.messages.in b/Source/WebKit/UIProcess/WebPageProxy.messages.in
index e39dc25bbd8f8b15d66818f6d6d82a3b56999492..4feb0a252910f0cd0ac5baa35f34b8d42699a4c5 100644
--- a/Source/WebKit/UIProcess/WebPageProxy.messages.in
+++ b/Source/WebKit/UIProcess/WebPageProxy.messages.in
@@ -29,6 +29,7 @@ messages -> WebPageProxy {
     RunJavaScriptConfirm(WebCore::FrameIdentifier frameID, struct WebCore::SecurityOriginData frameSecurityOrigin, String message) -> (bool result) Synchronous
     RunJavaScriptPrompt(WebCore::FrameIdentifier frameID, struct WebCore::SecurityOriginData frameSecurityOrigin, String message, String defaultValue) -> (String result) Synchronous
     MouseDidMoveOverElement(struct WebKit::WebHitTestResultData hitTestResultData, uint32_t modifiers, WebKit::UserData userData)
+    LogToStderr(String text)
 
 #if ENABLE(NETSCAPE_PLUGIN_API)
     UnavailablePluginButtonClicked(uint32_t pluginUnavailabilityReason, String mimeType, String pluginURLString, String pluginspageAttributeURLString, String frameURLString, String pageURLString)
@@ -209,6 +210,7 @@ messages -> WebPageProxy {
     FindStringCallback(bool found, WebKit::CallbackID callbackID)
 
     PageScaleFactorDidChange(double scaleFactor)
+    ViewScaleFactorDidChange(double scaleFactor)
     PluginScaleFactorDidChange(double zoomFactor)
     PluginZoomFactorDidChange(double zoomFactor)
 
diff --git a/Source/WebKit/UIProcess/WebProcessPool.cpp b/Source/WebKit/UIProcess/WebProcessPool.cpp
index bee7803a92d3d5077da8ed0d14329637d4bdf796..bfbd9b95dd1f565dd9ba9a61e882d1c43838778c 100644
--- a/Source/WebKit/UIProcess/WebProcessPool.cpp
+++ b/Source/WebKit/UIProcess/WebProcessPool.cpp
@@ -423,12 +423,19 @@ void WebProcessPool::languageChanged(void* context)
     static_cast<WebProcessPool*>(context)->languageChanged();
 }
 
+void WebProcessPool::setLanguagesForAutomation(Vector<String>&& languages)
+{
+    m_languagesForAutomation = WTFMove(languages);
+    languageChanged();
+}
+
 void WebProcessPool::languageChanged()
 {
-    sendToAllProcesses(Messages::WebProcess::UserPreferredLanguagesChanged(userPreferredLanguages()));
+    const Vector<String>& languages = m_languagesForAutomation.size() ? m_languagesForAutomation : userPreferredLanguages();
+    sendToAllProcesses(Messages::WebProcess::UserPreferredLanguagesChanged(languages));
 #if USE(SOUP)
     if (m_networkProcess)
-        m_networkProcess->send(Messages::NetworkProcess::UserPreferredLanguagesChanged(userPreferredLanguages()), 0);
+        m_networkProcess->send(Messages::NetworkProcess::UserPreferredLanguagesChanged(languages), 0);
 #endif
 }
 
@@ -985,7 +992,10 @@ void WebProcessPool::initializeNewWebProcess(WebProcessProxy& process, WebsiteDa
 #endif
 
     parameters.cacheModel = LegacyGlobalSettings::singleton().cacheModel();
-    parameters.languages = configuration().overrideLanguages().isEmpty() ? userPreferredLanguages() : configuration().overrideLanguages();
+    if (m_languagesForAutomation.size())
+        parameters.languages = m_languagesForAutomation;
+    else
+        parameters.languages = configuration().overrideLanguages().isEmpty() ? userPreferredLanguages() : configuration().overrideLanguages();
 
     parameters.urlSchemesRegisteredAsEmptyDocument = copyToVector(m_schemesToRegisterAsEmptyDocument);
     parameters.urlSchemesRegisteredAsSecure = copyToVector(LegacyGlobalSettings::singleton().schemesToRegisterAsSecure());
diff --git a/Source/WebKit/UIProcess/WebProcessPool.h b/Source/WebKit/UIProcess/WebProcessPool.h
index 06105866ef203680ffeaf2876c1efae80b76808a..8f9d933071a2aa05fdf8d6d11ffd911f96013623 100644
--- a/Source/WebKit/UIProcess/WebProcessPool.h
+++ b/Source/WebKit/UIProcess/WebProcessPool.h
@@ -417,7 +417,7 @@ public:
 
     void windowServerConnectionStateChanged();
 
-#if USE(SOUP)
+#if USE(SOUP) || PLATFORM(COCOA) || PLATFORM(WIN)
     void setIgnoreTLSErrors(bool);
     bool ignoreTLSErrors() const { return m_ignoreTLSErrors; }
 #endif
@@ -538,6 +538,8 @@ public:
     
     PlugInAutoStartProvider& plugInAutoStartProvider() { return m_plugInAutoStartProvider; }
 
+    void setLanguagesForAutomation(Vector<String>&&);
+
     void setUseSeparateServiceWorkerProcess(bool);
     bool useSeparateServiceWorkerProcess() const { return m_useSeparateServiceWorkerProcess; }
 
@@ -650,6 +652,7 @@ private:
     std::unique_ptr<API::CustomProtocolManagerClient> m_customProtocolManagerClient;
 
     RefPtr<WebAutomationSession> m_automationSession;
+    Vector<String> m_languagesForAutomation;
 
 #if ENABLE(NETSCAPE_PLUGIN_API)
     PluginInfoStore m_pluginInfoStore;
@@ -719,8 +722,8 @@ private:
     HashMap<uint64_t, RefPtr<DictionaryCallback>> m_dictionaryCallbacks;
     HashMap<uint64_t, RefPtr<StatisticsRequest>> m_statisticsRequests;
 
-#if USE(SOUP)
-    bool m_ignoreTLSErrors { true };
+#if USE(SOUP) || PLATFORM(COCOA) || PLATFORM(WIN)
+    bool m_ignoreTLSErrors { false };
 #endif
 
     bool m_memoryCacheDisabled { false };
diff --git a/Source/WebKit/UIProcess/geoclue/GeoclueGeolocationProvider.cpp b/Source/WebKit/UIProcess/geoclue/GeoclueGeolocationProvider.cpp
index 7ba39332bce6e28f0f4b2f7acf636f835c54f486..7c3d8125df147b6049075491b12cce1dc84bf514 100644
--- a/Source/WebKit/UIProcess/geoclue/GeoclueGeolocationProvider.cpp
+++ b/Source/WebKit/UIProcess/geoclue/GeoclueGeolocationProvider.cpp
@@ -60,6 +60,8 @@ void GeoclueGeolocationProvider::start(UpdateNotifyFunction&& updateNotifyFuncti
     m_isRunning = true;
     m_cancellable = adoptGRef(g_cancellable_new());
     if (!m_manager) {
+        g_cancellable_cancel(m_cancellable_start.get());
+        m_cancellable_start = adoptGRef(g_cancellable_new());
         g_dbus_proxy_new_for_bus(G_BUS_TYPE_SYSTEM, G_DBUS_PROXY_FLAGS_NONE, nullptr,
             "org.freedesktop.GeoClue2", "/org/freedesktop/GeoClue2/Manager", "org.freedesktop.GeoClue2.Manager", m_cancellable.get(),
             [](GObject*, GAsyncResult* result, gpointer userData) {
@@ -91,6 +93,12 @@ void GeoclueGeolocationProvider::stop()
     g_cancellable_cancel(m_cancellable.get());
     m_cancellable = nullptr;
     stopClient();
+    g_cancellable_cancel(m_cancellable_start.get());
+    m_cancellable_start = nullptr;
+    g_cancellable_cancel(m_cancellable_setup.get());
+    m_cancellable_setup = nullptr;
+    g_cancellable_cancel(m_cancellable_create.get());
+    m_cancellable_create = nullptr;
     destroyManagerLater();
 }
 
@@ -153,6 +161,8 @@ void GeoclueGeolocationProvider::createClient(const char* clientPath)
         return;
     }
 
+    g_cancellable_cancel(m_cancellable_create.get());
+    m_cancellable_create = adoptGRef(g_cancellable_new());
     g_dbus_proxy_new_for_bus(G_BUS_TYPE_SYSTEM, G_DBUS_PROXY_FLAGS_NONE, nullptr,
         "org.freedesktop.GeoClue2", clientPath, "org.freedesktop.GeoClue2.Client", m_cancellable.get(),
         [](GObject*, GAsyncResult* result, gpointer userData) {
diff --git a/Source/WebKit/UIProcess/geoclue/GeoclueGeolocationProvider.h b/Source/WebKit/UIProcess/geoclue/GeoclueGeolocationProvider.h
index 31d29091985f34a65134a2b0e7cb3ace1dae441d..571ceac8a4b291fa6e91eb8b17065c0aba908ac3 100644
--- a/Source/WebKit/UIProcess/geoclue/GeoclueGeolocationProvider.h
+++ b/Source/WebKit/UIProcess/geoclue/GeoclueGeolocationProvider.h
@@ -71,6 +71,9 @@ private:
     GRefPtr<GDBusProxy> m_manager;
     GRefPtr<GDBusProxy> m_client;
     GRefPtr<GCancellable> m_cancellable;
+    GRefPtr<GCancellable> m_cancellable_start;
+    GRefPtr<GCancellable> m_cancellable_setup;
+    GRefPtr<GCancellable> m_cancellable_create;
     UpdateNotifyFunction m_updateNotifyFunction;
     RunLoop::Timer<GeoclueGeolocationProvider> m_destroyManagerLaterTimer;
 };
diff --git a/Source/WebKit/UIProcess/glib/InspectorBrowserAgentClientGLib.cpp b/Source/WebKit/UIProcess/glib/InspectorBrowserAgentClientGLib.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..0038b09d06d3d92b885d70bfffa9b111766b3f57
--- /dev/null
+++ b/Source/WebKit/UIProcess/glib/InspectorBrowserAgentClientGLib.cpp
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "InspectorBrowserAgentClientGLib.h"
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "InspectorBrowserAgent.h"
+#include "WebKitBrowserInspectorPrivate.h"
+#include "WebKitWebContextPrivate.h"
+#include "WebKitWebsiteDataManagerPrivate.h"
+#include "WebKitWebViewPrivate.h"
+#include "WebPageProxy.h"
+#include <wtf/HashMap.h>
+#include <wtf/RefPtr.h>
+#include <wtf/text/StringView.h>
+#include <wtf/text/WTFString.h>
+
+namespace WebKit {
+
+InspectorBrowserAgentClientGlib::InspectorBrowserAgentClientGlib(GMainLoop* mainLoop)
+    : m_mainLoop(mainLoop)
+{
+}
+
+RefPtr<WebPageProxy> InspectorBrowserAgentClientGlib::createPage(WTF::String& error, const BrowserContext& browserContext)
+{
+    auto sessionID = browserContext.dataStore->sessionID();
+    WebKitWebContext* context = m_idToContext.get(sessionID);
+    if (!context && !browserContext.dataStore->isPersistent()) {
+        ASSERT_NOT_REACHED();
+        error = "Context with provided id not found";
+        return nullptr;
+    }
+
+    RefPtr<WebPageProxy> page = webkitBrowserInspectorCreateNewPageInContext(context);
+    if (page == nullptr) {
+        error = "Failed to create new page in the context";
+        return nullptr;
+    }
+
+    if (context == nullptr && sessionID != page->sessionID()) {
+        ASSERT_NOT_REACHED();
+        error = " Failed to create new page in default context";
+        return nullptr;
+    }
+
+    return page;
+}
+
+void InspectorBrowserAgentClientGlib::closeBrowser()
+{
+    m_idToContext.clear();
+#if PLATFORM(GTK)
+    gtk_main_quit();
+#else
+    if (m_mainLoop)
+        g_main_loop_quit(m_mainLoop);
+#endif
+}
+
+static PAL::SessionID sessionIDFromContext(WebKitWebContext* context)
+{
+    WebKitWebsiteDataManager* data_manager = webkit_web_context_get_website_data_manager(context);
+    WebsiteDataStore& websiteDataStore = webkitWebsiteDataManagerGetDataStore(data_manager);
+    return websiteDataStore.sessionID();
+}
+
+BrowserContext InspectorBrowserAgentClientGlib::createBrowserContext(WTF::String& error)
+{
+    BrowserContext browserContext;
+    GRefPtr<WebKitWebsiteDataManager> data_manager = adoptGRef(webkit_website_data_manager_new_ephemeral());
+    GRefPtr<WebKitWebContext> context = adoptGRef(WEBKIT_WEB_CONTEXT(g_object_new(WEBKIT_TYPE_WEB_CONTEXT, "website-data-manager", data_manager.get(), "process-swap-on-cross-site-navigation-enabled", true, nullptr)));
+    if (!context) {
+        error = "Failed to create GLib ephemeral context";
+        return browserContext;
+    }
+    browserContext.processPool = &webkitWebContextGetProcessPool(context.get());
+    browserContext.dataStore = &webkitWebsiteDataManagerGetDataStore(data_manager.get());
+    PAL::SessionID sessionID = sessionIDFromContext(context.get());
+    m_idToContext.set(sessionID, WTFMove(context));
+    return browserContext;
+}
+
+void InspectorBrowserAgentClientGlib::deleteBrowserContext(WTF::String& error, PAL::SessionID sessionID)
+{
+    m_idToContext.remove(sessionID);
+}
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/glib/InspectorBrowserAgentClientGLib.h b/Source/WebKit/UIProcess/glib/InspectorBrowserAgentClientGLib.h
new file mode 100644
index 0000000000000000000000000000000000000000..9e27fe017ffdef1e8aafce69344fd688c732c3b4
--- /dev/null
+++ b/Source/WebKit/UIProcess/glib/InspectorBrowserAgentClientGLib.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "InspectorBrowserAgentClient.h"
+#include "WebKitWebContext.h"
+#include <wtf/Forward.h>
+#include <wtf/HashMap.h>
+#include <wtf/glib/GRefPtr.h>
+#include <wtf/text/StringHash.h>
+
+namespace WebKit {
+
+class InspectorBrowserAgentClientGlib : public InspectorBrowserAgentClient {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    InspectorBrowserAgentClientGlib(GMainLoop* mainLoop);
+    ~InspectorBrowserAgentClientGlib() override = default;
+
+    RefPtr<WebPageProxy> createPage(WTF::String& error, const BrowserContext&) override;
+    void closeBrowser() override;
+    BrowserContext createBrowserContext(WTF::String& error) override;
+    void deleteBrowserContext(WTF::String& error, PAL::SessionID) override;
+
+private:
+    WebKitWebContext* findContext(WTF::String& error, PAL::SessionID);
+
+    HashMap<PAL::SessionID, GRefPtr<WebKitWebContext>> m_idToContext;
+    GMainLoop* m_mainLoop;
+};
+
+} // namespace API
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/gtk/InspectorTargetProxyGtk.cpp b/Source/WebKit/UIProcess/gtk/InspectorTargetProxyGtk.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..8a86cc348bc210b71bb463dcb3057f575ad7c1d3
--- /dev/null
+++ b/Source/WebKit/UIProcess/gtk/InspectorTargetProxyGtk.cpp
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "InspectorTargetProxy.h"
+
+#include "WebPageProxy.h"
+#include <WebCore/GtkUtilities.h>
+#include <gtk/gtk.h>
+
+namespace WebKit {
+
+void InspectorTargetProxy::platformActivate(String& error) const
+{
+    GtkWidget* parent = gtk_widget_get_toplevel(m_page.viewWidget());
+    if (WebCore::widgetIsOnscreenToplevelWindow(parent))
+        gtk_window_present(GTK_WINDOW(parent));
+    else
+        error = "The view is not on screen";
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/gtk/WebPageInspectorEmulationAgentGtk.cpp b/Source/WebKit/UIProcess/gtk/WebPageInspectorEmulationAgentGtk.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e5e25acebabb76a05a77db02a99f1267bd99a3af
--- /dev/null
+++ b/Source/WebKit/UIProcess/gtk/WebPageInspectorEmulationAgentGtk.cpp
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "DrawingAreaProxyCoordinatedGraphics.h"
+#include "WebPageInspectorEmulationAgent.h"
+#include "WebPageProxy.h"
+#include <WebCore/IntSize.h>
+#include <gtk/gtk.h>
+
+namespace WebKit {
+void WebPageInspectorEmulationAgent::platformSetSize(int width, int height, Function<void (const String& error)>&& callback)
+{
+    GtkWidget* viewWidget = m_page.viewWidget();
+    GtkWidget* window = gtk_widget_get_toplevel(viewWidget);
+    if (!window) {
+        callback("Cannot find parent window"_s);
+        return;
+    }
+    if (!GTK_IS_WINDOW(window)) {
+        callback("Toplevel is not a window"_s);
+        return;
+    }
+    GtkAllocation viewAllocation;
+    gtk_widget_get_allocation(viewWidget, &viewAllocation);
+    if (viewAllocation.width == width && viewAllocation.height == height) {
+        callback(String());
+        return;
+    }
+
+    GtkAllocation windowAllocation;
+    gtk_widget_get_allocation(window, &windowAllocation);
+
+    width += windowAllocation.width - viewAllocation.width;
+    height += windowAllocation.height - viewAllocation.height;
+
+    if (auto* drawingArea = static_cast<DrawingAreaProxyCoordinatedGraphics*>(m_page.drawingArea())) {
+        drawingArea->waitForSizeUpdate([callback = WTFMove(callback)]() {
+            callback(String());
+        });
+    } else {
+        callback("No backing store for window"_s);
+    }
+    gtk_window_resize(GTK_WINDOW(window), width, height);
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/gtk/WebPageInspectorInputAgentGtk.cpp b/Source/WebKit/UIProcess/gtk/WebPageInspectorInputAgentGtk.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..7ad3fe416c5c747eaad8c6948c3549a3984223ea
--- /dev/null
+++ b/Source/WebKit/UIProcess/gtk/WebPageInspectorInputAgentGtk.cpp
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "WebPageInspectorInputAgent.h"
+
+#include "KeyBindingTranslator.h"
+#include "NativeWebKeyboardEvent.h"
+#include "WebPageProxy.h"
+#include <WebCore/PlatformKeyboardEvent.h>
+
+namespace WebKit {
+
+static Vector<String> commandsForKeyEvent(GdkEventType type, unsigned keyVal, unsigned state)
+{
+    ASSERT(type == GDK_KEY_PRESS || type == GDK_KEY_RELEASE);
+
+    GUniquePtr<GdkEvent> event(gdk_event_new(type));
+    event->key.keyval = keyVal;
+    event->key.time = GDK_CURRENT_TIME;
+    event->key.state = state;
+    // When synthesizing an event, an invalid hardware_keycode value can cause it to be badly processed by GTK+.
+    GUniqueOutPtr<GdkKeymapKey> keys;
+    int keysCount;
+    if (gdk_keymap_get_entries_for_keyval(gdk_keymap_get_default(), keyVal, &keys.outPtr(), &keysCount) && keysCount)
+        event->key.hardware_keycode = keys.get()[0].keycode;
+    return KeyBindingTranslator().commandsForKeyEvent(&event->key);
+}
+
+static unsigned modifiersToEventState(OptionSet<WebEvent::Modifier> modifiers)
+{
+    unsigned state = 0;
+    if (modifiers.contains(WebEvent::Modifier::ControlKey))
+        state |= GDK_CONTROL_MASK;
+    if (modifiers.contains(WebEvent::Modifier::ShiftKey))
+        state |= GDK_SHIFT_MASK;
+    if (modifiers.contains(WebEvent::Modifier::AltKey))
+        state |= GDK_META_MASK;
+    if (modifiers.contains(WebEvent::Modifier::CapsLockKey))
+        state |= GDK_LOCK_MASK;
+    return state;
+}
+
+void WebPageInspectorInputAgent::platformDispatchKeyEvent(WebKeyboardEvent::Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<WebEvent::Modifier> modifiers, Vector<String>& macCommands, WallTime timestamp)
+{
+    Vector<String> commands;
+    const guint keyVal = WebCore::PlatformKeyboardEvent::gdkKeyCodeForWindowsKeyCode(windowsVirtualKeyCode);
+    String keyIdentifier;
+    if (keyVal) {
+        GdkEventType event = GDK_NOTHING;
+        switch (type)
+        {
+        case WebKeyboardEvent::KeyDown:
+            event = GDK_KEY_PRESS;
+            break;
+        case WebKeyboardEvent::KeyUp:
+            event = GDK_KEY_RELEASE;
+            break;
+        default:
+            fprintf(stderr, "Unsupported event type = %d\n", type);
+            break;
+        }
+        unsigned state = modifiersToEventState(modifiers);
+        commands = commandsForKeyEvent(event, keyVal, state);
+        keyIdentifier = WebCore::PlatformKeyboardEvent::keyIdentifierForGdkKeyCode(keyVal);
+    }
+    NativeWebKeyboardEvent event(
+        type,
+        text,
+        unmodifiedText,
+        key,
+        code,
+        keyIdentifier,
+        windowsVirtualKeyCode,
+        nativeVirtualKeyCode,
+        isAutoRepeat,
+        isKeypad,
+        isSystemKey,
+        modifiers,
+        timestamp,
+        WTFMove(commands));
+    m_page.handleKeyboardEvent(event);
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/ios/PageClientImplIOS.mm b/Source/WebKit/UIProcess/ios/PageClientImplIOS.mm
index 82b89cf43f3d903daea3234dc5fc57e749401c81..8df94bc82061eea191598bf0ab0ca1abbb50283c 100644
--- a/Source/WebKit/UIProcess/ios/PageClientImplIOS.mm
+++ b/Source/WebKit/UIProcess/ios/PageClientImplIOS.mm
@@ -450,6 +450,8 @@ IntRect PageClientImpl::rootViewToAccessibilityScreen(const IntRect& rect)
     
 void PageClientImpl::doneWithKeyEvent(const NativeWebKeyboardEvent& event, bool eventWasHandled)
 {
+    if (!event.nativeEvent())
+        return;
     [m_contentView _didHandleKeyEvent:event.nativeEvent() eventWasHandled:eventWasHandled];
 }
 
diff --git a/Source/WebKit/UIProcess/mac/InspectorBrowserAgentClientMac.h b/Source/WebKit/UIProcess/mac/InspectorBrowserAgentClientMac.h
new file mode 100644
index 0000000000000000000000000000000000000000..f9e7e5906301bb7add100bba3f88c0c0aef04fd1
--- /dev/null
+++ b/Source/WebKit/UIProcess/mac/InspectorBrowserAgentClientMac.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "InspectorBrowserAgentClient.h"
+#include <wtf/Forward.h>
+
+OBJC_PROTOCOL(_WKBrowserInspectorDelegate);
+
+namespace WebKit {
+
+class InspectorBrowserAgentClientMac : public InspectorBrowserAgentClient {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    InspectorBrowserAgentClientMac(_WKBrowserInspectorDelegate* delegate);
+    ~InspectorBrowserAgentClientMac() override = default;
+
+    RefPtr<WebPageProxy> createPage(WTF::String& error, const BrowserContext&) override;
+    void closeBrowser() override;
+    BrowserContext createBrowserContext(WTF::String& error) override;
+    void deleteBrowserContext(WTF::String& error, PAL::SessionID) override;
+
+private:
+    _WKBrowserInspectorDelegate* delegate_;
+};
+
+
+} // namespace API
diff --git a/Source/WebKit/UIProcess/mac/InspectorBrowserAgentClientMac.mm b/Source/WebKit/UIProcess/mac/InspectorBrowserAgentClientMac.mm
new file mode 100644
index 0000000000000000000000000000000000000000..fc40a8a0ee3f88a4f15d5b75f060b00e1126f47b
--- /dev/null
+++ b/Source/WebKit/UIProcess/mac/InspectorBrowserAgentClientMac.mm
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "config.h"
+#import "InspectorBrowserAgentClientMac.h"
+
+#import <wtf/RefPtr.h>
+#import <wtf/text/WTFString.h>
+#import "WebPageProxy.h"
+#import "WebProcessPool.h"
+#import "WebsiteDataStore.h"
+#import "_WKBrowserInspector.h"
+#import "WKProcessPoolInternal.h"
+#import "WKWebsiteDataStoreInternal.h"
+#import "WKWebView.h"
+#import "WKWebViewInternal.h"
+
+namespace WebKit {
+
+InspectorBrowserAgentClientMac::InspectorBrowserAgentClientMac(_WKBrowserInspectorDelegate* delegate)
+  : delegate_(delegate)
+{
+}
+
+RefPtr<WebPageProxy> InspectorBrowserAgentClientMac::createPage(WTF::String& error, const BrowserContext& browserContext)
+{
+    auto sessionID = browserContext.dataStore->sessionID();
+    WKWebView *webView = [delegate_ createNewPage:sessionID.toUInt64()];
+    if (!webView) {
+        error = "Internal error: can't create page in given context"_s;
+        return nil;
+    }
+    return [webView _page].get();
+}
+
+void InspectorBrowserAgentClientMac::closeBrowser()
+{
+    [delegate_ quit];
+}
+
+BrowserContext InspectorBrowserAgentClientMac::createBrowserContext(WTF::String& error)
+{
+    _WKBrowserContext* wkBrowserContext = [[delegate_ createBrowserContext] autorelease];
+    BrowserContext browserContext;
+    browserContext.processPool = &static_cast<WebProcessPool&>([[wkBrowserContext processPool] _apiObject]);
+    browserContext.dataStore = &static_cast<WebsiteDataStore&>([[wkBrowserContext dataStore] _apiObject]);
+    return browserContext;
+}
+
+void InspectorBrowserAgentClientMac::deleteBrowserContext(WTF::String& error, PAL::SessionID sessionID)
+{
+    [delegate_ deleteBrowserContext:sessionID.toUInt64()];
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/mac/InspectorTargetProxyMac.mm b/Source/WebKit/UIProcess/mac/InspectorTargetProxyMac.mm
new file mode 100644
index 0000000000000000000000000000000000000000..721826c8c98fc85b68a4f45deaee69c1219a7254
--- /dev/null
+++ b/Source/WebKit/UIProcess/mac/InspectorTargetProxyMac.mm
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "config.h"
+#import "InspectorTargetProxy.h"
+#import "WebPageProxy.h"
+
+#if PLATFORM(MAC)
+
+namespace WebKit {
+
+void InspectorTargetProxy::platformActivate(String& error) const
+{
+    NSWindow* window = m_page.platformWindow();
+    [window makeKeyAndOrderFront:nil];
+}
+
+} // namespace WebKit
+
+#endif
diff --git a/Source/WebKit/UIProcess/mac/PageClientImplMac.h b/Source/WebKit/UIProcess/mac/PageClientImplMac.h
index 0dca8706d42603578612cc77add0babb05f4e8d5..7a17fd28ed76abfaf36675bf472812f02f0e8b58 100644
--- a/Source/WebKit/UIProcess/mac/PageClientImplMac.h
+++ b/Source/WebKit/UIProcess/mac/PageClientImplMac.h
@@ -53,6 +53,8 @@ class PageClientImpl final : public PageClientImplCocoa
 #endif
     {
 public:
+    static void setHeadless(bool headless);
+
     PageClientImpl(NSView *, WKWebView *);
     virtual ~PageClientImpl();
 
@@ -206,6 +208,10 @@ private:
     void beganExitFullScreen(const WebCore::IntRect& initialFrame, const WebCore::IntRect& finalFrame) override;
 #endif
 
+#if ENABLE(TOUCH_EVENTS)
+    void doneWithTouchEvent(const NativeWebTouchEvent&, bool wasEventHandled) override;
+#endif
+
     void navigationGestureDidBegin() override;
     void navigationGestureWillEnd(bool willNavigate, WebBackForwardListItem&) override;
     void navigationGestureDidEnd(bool willNavigate, WebBackForwardListItem&) override;
diff --git a/Source/WebKit/UIProcess/mac/PageClientImplMac.mm b/Source/WebKit/UIProcess/mac/PageClientImplMac.mm
index af376ae653ab8bffeca10e070954dcdf1ed3de3d..eefb0da9904f41794b328e236bb022804e92e8d4 100644
--- a/Source/WebKit/UIProcess/mac/PageClientImplMac.mm
+++ b/Source/WebKit/UIProcess/mac/PageClientImplMac.mm
@@ -78,6 +78,7 @@
 #import <WebCore/TextUndoInsertionMarkupMac.h>
 #import <WebCore/ValidationBubble.h>
 #import <WebCore/WebCoreCALayerExtras.h>
+#import <WebCore/NotImplemented.h>
 #import <wtf/ProcessPrivilege.h>
 #import <wtf/text/CString.h>
 #import <wtf/text/WTFString.h>
@@ -105,6 +106,13 @@ static NSString * const kAXLoadCompleteNotification = @"AXLoadComplete";
 namespace WebKit {
 using namespace WebCore;
 
+static bool _headless = false;
+
+// static
+void PageClientImpl::setHeadless(bool headless) {
+    _headless = true;
+}
+
 PageClientImpl::PageClientImpl(NSView* view, WKWebView *webView)
     : PageClientImplCocoa(webView)
     , m_view(view)
@@ -163,6 +171,9 @@ NSWindow *PageClientImpl::activeWindow() const
 
 bool PageClientImpl::isViewWindowActive()
 {
+    if (_headless)
+        return true;
+
     ASSERT(hasProcessPrivilege(ProcessPrivilege::CanCommunicateWithWindowServer));
     NSWindow *activeViewWindow = activeWindow();
     return activeViewWindow.isKeyWindow || [NSApp keyWindow] == activeViewWindow;
@@ -170,6 +181,9 @@ bool PageClientImpl::isViewWindowActive()
 
 bool PageClientImpl::isViewFocused()
 {
+    if (_headless)
+        return true;
+
     // FIXME: This is called from the WebPageProxy constructor before we have a WebViewImpl.
     // Once WebViewImpl and PageClient merge, this won't be a problem.
     if (!m_impl)
@@ -193,6 +207,9 @@ void PageClientImpl::makeFirstResponder()
     
 bool PageClientImpl::isViewVisible()
 {
+    if (_headless)
+        return true;
+
     NSView *activeView = this->activeView();
     NSWindow *activeViewWindow = activeWindow();
 
@@ -278,7 +295,8 @@ void PageClientImpl::didRelaunchProcess()
 
 void PageClientImpl::preferencesDidChange()
 {
-    m_impl->preferencesDidChange();
+    if (m_impl)
+        m_impl->preferencesDidChange();
 }
 
 void PageClientImpl::toolTipChanged(const String& oldToolTip, const String& newToolTip)
@@ -456,6 +474,8 @@ IntRect PageClientImpl::rootViewToAccessibilityScreen(const IntRect& rect)
 
 void PageClientImpl::doneWithKeyEvent(const NativeWebKeyboardEvent& event, bool eventWasHandled)
 {
+    if (!event.nativeEvent())
+        return;
     m_impl->doneWithKeyEvent(event.nativeEvent(), eventWasHandled);
 }
 
@@ -760,6 +780,13 @@ void PageClientImpl::beganExitFullScreen(const IntRect& initialFrame, const IntR
 
 #endif // ENABLE(FULLSCREEN_API)
 
+#if ENABLE(TOUCH_EVENTS)
+void PageClientImpl::doneWithTouchEvent(const NativeWebTouchEvent& event, bool wasEventHandled)
+{
+    notImplemented();
+}
+#endif // ENABLE(TOUCH_EVENTS)
+
 void PageClientImpl::navigationGestureDidBegin()
 {
     m_impl->dismissContentRelativeChildWindowsWithAnimation(true);
@@ -926,6 +953,9 @@ void PageClientImpl::didRestoreScrollPosition()
 
 bool PageClientImpl::windowIsFrontWindowUnderMouse(const NativeWebMouseEvent& event)
 {
+    // Simulated event.
+    if (!event.nativeEvent())
+        return false;
     return m_impl->windowIsFrontWindowUnderMouse(event.nativeEvent());
 }
 
diff --git a/Source/WebKit/UIProcess/mac/WebPageInspectorEmulationAgentMac.mm b/Source/WebKit/UIProcess/mac/WebPageInspectorEmulationAgentMac.mm
new file mode 100644
index 0000000000000000000000000000000000000000..6113f4cd60a5d72b8ead61176cb43200803478ed
--- /dev/null
+++ b/Source/WebKit/UIProcess/mac/WebPageInspectorEmulationAgentMac.mm
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "config.h"
+#import "WebPageInspectorEmulationAgent.h"
+
+#import "WebPageProxy.h"
+
+namespace WebKit {
+
+void WebPageInspectorEmulationAgent::platformSetSize(int width, int height, Function<void (const String& error)>&& callback)
+{
+    NSWindow* window = m_page.platformWindow();
+    NSRect windowRect = [window frame];
+    NSRect viewRect = window.contentLayoutRect;
+    windowRect.size.width += width - viewRect.size.width;
+    windowRect.size.height += height - viewRect.size.height;
+    [window setFrame:windowRect display:YES animate:NO];
+    callback(String());
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/mac/WebPageInspectorInputAgentMac.mm b/Source/WebKit/UIProcess/mac/WebPageInspectorInputAgentMac.mm
new file mode 100644
index 0000000000000000000000000000000000000000..30e6ae3bdc8c1695189885afae949071add54c4e
--- /dev/null
+++ b/Source/WebKit/UIProcess/mac/WebPageInspectorInputAgentMac.mm
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "config.h"
+#import "NativeWebMouseEvent.h"
+#import "WebPageInspectorInputAgent.h"
+#import "WebPageProxy.h"
+#import <WebCore/IntPoint.h>
+#import <WebCore/IntSize.h>
+#import "NativeWebKeyboardEvent.h"
+#import <wtf/HexNumber.h>
+
+namespace WebKit {
+
+using namespace WebCore;
+
+void WebPageInspectorInputAgent::platformDispatchMouseEvent(const String& type, int x, int y, const int* optionalModifiers, const String* button, const int* optionalClickCount) {
+    IntPoint locationInWindow(x, y);
+
+    NSEventModifierFlags modifiers = 0;
+    if (optionalModifiers) {
+        int inputModifiers = *optionalModifiers;
+        if (inputModifiers & 1)
+            modifiers |= NSEventModifierFlagShift;
+        if (inputModifiers & 2)
+            modifiers |= NSEventModifierFlagControl;
+        if (inputModifiers & 4)
+            modifiers |= NSEventModifierFlagOption;
+        if (inputModifiers & 8)
+            modifiers |= NSEventModifierFlagCommand;
+    }
+    int clickCount = optionalClickCount ? *optionalClickCount : 0;
+
+    NSTimeInterval timestamp = [NSDate timeIntervalSinceReferenceDate];
+    NSWindow *window = m_page.platformWindow();
+    NSInteger windowNumber = window.windowNumber;
+
+    NSEventType downEventType = (NSEventType)0;
+    NSEventType dragEventType = (NSEventType)0;
+    NSEventType upEventType = (NSEventType)0;
+
+    if (!button || *button == "none") {
+        downEventType = NSEventTypeMouseMoved;
+        dragEventType = NSEventTypeMouseMoved;
+        upEventType = NSEventTypeMouseMoved;
+    } else if (*button == "left") {
+        downEventType = NSEventTypeLeftMouseDown;
+        dragEventType = NSEventTypeLeftMouseDragged;
+        upEventType = NSEventTypeLeftMouseUp;
+    } else if (*button == "middle") {
+        downEventType = NSEventTypeOtherMouseDown;
+        dragEventType = NSEventTypeLeftMouseDragged;
+        upEventType = NSEventTypeOtherMouseUp;
+    } else if (*button == "right") {
+        downEventType = NSEventTypeRightMouseDown;
+        upEventType = NSEventTypeRightMouseUp;
+    }
+
+    NSInteger eventNumber = 0;
+
+    NSEvent* event = nil;
+    if (type == "move") {
+        event = [NSEvent mouseEventWithType:dragEventType location:locationInWindow modifierFlags:modifiers timestamp:timestamp windowNumber:windowNumber context:nil eventNumber:eventNumber clickCount:clickCount pressure:0.0f];
+    } else if (type == "down") {
+        event = [NSEvent mouseEventWithType:downEventType location:locationInWindow modifierFlags:modifiers timestamp:timestamp windowNumber:windowNumber context:nil eventNumber:eventNumber clickCount:clickCount pressure:WebCore::ForceAtClick];
+    } else if (type == "up") {
+        event = [NSEvent mouseEventWithType:upEventType location:locationInWindow modifierFlags:modifiers timestamp:timestamp windowNumber:windowNumber context:nil eventNumber:eventNumber clickCount:clickCount pressure:0.0f];
+    }
+
+    if (event) {
+        NativeWebMouseEvent nativeEvent(event, nil, [window contentView]);
+        m_page.handleMouseEvent(nativeEvent);
+    }
+}
+
+void WebPageInspectorInputAgent::platformDispatchKeyEvent(WebKeyboardEvent::Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<WebEvent::Modifier> modifiers, Vector<String>& commands, WallTime timestamp)
+{
+    String keyIdentifier = key.length() == 1 ? makeString("U+", hex(toASCIIUpper(key.characterAt(0)), 4)) : key;
+    Vector<WebCore::KeypressCommand> macCommands;
+    for (const String& command : commands)
+      macCommands.append(WebCore::KeypressCommand(command.utf8().data()));
+    if (text.length() > 0 && macCommands.size() == 0)
+      macCommands.append(WebCore::KeypressCommand("insertText:", text));
+    NativeWebKeyboardEvent event(
+        type,
+        text,
+        unmodifiedText,
+        key,
+        code,
+        keyIdentifier,
+        windowsVirtualKeyCode,
+        nativeVirtualKeyCode,
+        isAutoRepeat,
+        isKeypad,
+        isSystemKey,
+        modifiers,
+        timestamp,
+        WTFMove(macCommands));
+    m_page.handleKeyboardEvent(event);
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/win/InspectorBrowserAgentClientWin.cpp b/Source/WebKit/UIProcess/win/InspectorBrowserAgentClientWin.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..7406306e47b4f3469db150eef6a71ac30e8f2f7a
--- /dev/null
+++ b/Source/WebKit/UIProcess/win/InspectorBrowserAgentClientWin.cpp
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2020 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "InspectorBrowserAgentClientWin.h"
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "APIPageConfiguration.h"
+#include "APIProcessPoolConfiguration.h"
+#include "InspectorBrowserAgent.h"
+#include "WebPageProxy.h"
+#include "WebsiteDataStore.h"
+#include "WebPreferences.h"
+#include "WebProcessPool.h"
+#include "WebView.h"
+#include "WKAPICast.h"
+#include <wtf/HashMap.h>
+#include <wtf/RefPtr.h>
+#include <wtf/text/StringView.h>
+#include <wtf/text/WTFString.h>
+
+namespace WebKit {
+
+InspectorBrowserAgentClientWin::InspectorBrowserAgentClientWin(CreatePageCallback createPage, QuitCallback quit)
+    : m_createPage(createPage)
+    , m_quit(quit)
+{
+}
+
+RefPtr<WebPageProxy> InspectorBrowserAgentClientWin::createPage(WTF::String& error, const BrowserContext& context)
+{
+    auto conf = API::PageConfiguration::create();
+    auto prefs = WebPreferences::create(String(), "WebKit2Automation.", "WebKit2Automation.");
+    conf->setProcessPool(context.processPool.get());
+    conf->setWebsiteDataStore(context.dataStore.get());
+    return toImpl(m_createPage(toAPI(&conf.get())));
+}
+
+void InspectorBrowserAgentClientWin::closeBrowser()
+{
+    m_quit();
+}
+
+BrowserContext InspectorBrowserAgentClientWin::createBrowserContext(WTF::String& error)
+{
+    auto config = API::ProcessPoolConfiguration::create();
+    BrowserContext browserContext;
+    browserContext.processPool = WebKit::WebProcessPool::create(config);
+    browserContext.dataStore = WebKit::WebsiteDataStore::createNonPersistent();
+    PAL::SessionID sessionID = browserContext.dataStore->sessionID();
+    return browserContext;
+}
+
+void InspectorBrowserAgentClientWin::deleteBrowserContext(WTF::String& error, PAL::SessionID sessionID)
+{
+}
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/win/InspectorBrowserAgentClientWin.h b/Source/WebKit/UIProcess/win/InspectorBrowserAgentClientWin.h
new file mode 100644
index 0000000000000000000000000000000000000000..2311841478469154473c259a4e0c669daf4644f9
--- /dev/null
+++ b/Source/WebKit/UIProcess/win/InspectorBrowserAgentClientWin.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2020 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "InspectorBrowserAgentClient.h"
+#include <WebKit/WKInspector.h>
+#include <wtf/Forward.h>
+#include <wtf/text/StringHash.h>
+
+typedef WKPageRef (*CreatePageCallback)(WKPageConfigurationRef configuration);
+typedef void (*QuitCallback)();
+
+namespace WebKit {
+
+class InspectorBrowserAgentClientWin : public InspectorBrowserAgentClient {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    InspectorBrowserAgentClientWin(CreatePageCallback, QuitCallback);
+    ~InspectorBrowserAgentClientWin() override = default;
+
+    RefPtr<WebPageProxy> createPage(WTF::String& error, const BrowserContext&) override;
+    void closeBrowser() override;
+    BrowserContext createBrowserContext(WTF::String& error) override;
+    void deleteBrowserContext(WTF::String& error, PAL::SessionID) override;
+
+private:
+    CreatePageCallback m_createPage;
+    QuitCallback m_quit;
+};
+
+} // namespace API
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/win/InspectorTargetProxyWin.cpp b/Source/WebKit/UIProcess/win/InspectorTargetProxyWin.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..135a60361fa8fbf907382625e7c8dd4ea64ceb94
--- /dev/null
+++ b/Source/WebKit/UIProcess/win/InspectorTargetProxyWin.cpp
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2020 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "InspectorTargetProxy.h"
+#include "WebPageProxy.h"
+
+namespace WebKit {
+
+void InspectorTargetProxy::platformActivate(String& error) const
+{
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/win/WebPageInspectorEmulationAgentWin.cpp b/Source/WebKit/UIProcess/win/WebPageInspectorEmulationAgentWin.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..520d9714bac279a8b778c2c377af4411fba8d5d7
--- /dev/null
+++ b/Source/WebKit/UIProcess/win/WebPageInspectorEmulationAgentWin.cpp
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2020 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "WebPageInspectorEmulationAgent.h"
+#include "WebPageProxy.h"
+
+namespace WebKit {
+
+void WebPageInspectorEmulationAgent::platformSetSize(int width, int height, Function<void (const String& error)>&& callback)
+{
+    HWND viewHwnd = m_page.viewWidget();
+    HWND windowHwnd = GetAncestor(viewHwnd, GA_ROOT);
+    RECT viewRect;
+    RECT windowRect;
+
+    if (!windowHwnd || !GetWindowRect(windowHwnd, &windowRect)) {
+        callback("Could not retrieve window size");
+        return;
+    }
+    if (!GetWindowRect(viewHwnd, &viewRect)) {
+        callback("Could retrieve view size");
+        return;
+    }
+
+    width += windowRect.right - windowRect.left - viewRect.right + viewRect.left;
+    height += windowRect.bottom - windowRect.top - viewRect.bottom + viewRect.top;
+
+    if (!SetWindowPos(windowHwnd, 0, 0, 0, width, height, SWP_NOMOVE)) {
+        callback("Could not resize window");
+        return;
+    }
+    callback(String());
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/win/WebPageInspectorInputAgentWin.cpp b/Source/WebKit/UIProcess/win/WebPageInspectorInputAgentWin.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..a299240b1fea96694cb47fa11fc6a6411ffdaf70
--- /dev/null
+++ b/Source/WebKit/UIProcess/win/WebPageInspectorInputAgentWin.cpp
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2020 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#include "config.h"
+#include "WebPageInspectorInputAgent.h"
+
+#include "NativeWebKeyboardEvent.h"
+#include "WebPageProxy.h"
+#include <WebCore/PlatformKeyboardEvent.h>
+
+namespace WebKit {
+
+void WebPageInspectorInputAgent::platformDispatchKeyEvent(WebKeyboardEvent::Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<WebEvent::Modifier> modifiers, Vector<String>& macCommands, WallTime timestamp)
+{
+    NativeWebKeyboardEvent event(
+        type,
+        text,
+        unmodifiedText,
+        key,
+        code,
+        "",
+        windowsVirtualKeyCode,
+        nativeVirtualKeyCode,
+        isAutoRepeat,
+        isKeypad,
+        isSystemKey,
+        modifiers,
+        timestamp);
+    m_page.handleKeyboardEvent(event);
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/win/WebProcessPoolWin.cpp b/Source/WebKit/UIProcess/win/WebProcessPoolWin.cpp
index 18f9e93932793b7c3e44e6346be0f13ed6dbf233..acb0617bcded07029665d4949659c73adf2fd633 100644
--- a/Source/WebKit/UIProcess/win/WebProcessPoolWin.cpp
+++ b/Source/WebKit/UIProcess/win/WebProcessPoolWin.cpp
@@ -26,7 +26,7 @@
 
 #include "config.h"
 #include "WebProcessPool.h"
-
+#include "NetworkProcessMessages.h"
 #include "WebProcessCreationParameters.h"
 #include <WebCore/NotImplemented.h>
 
@@ -97,4 +97,11 @@ void WebProcessPool::platformResolvePathsForSandboxExtensions()
 {
 }
 
+void WebProcessPool::setIgnoreTLSErrors(bool ignoreTLSErrors)
+{
+    m_ignoreTLSErrors = ignoreTLSErrors;
+    if (networkProcess())
+        networkProcess()->send(Messages::NetworkProcess::SetIgnoreTLSErrors(m_ignoreTLSErrors), 0);
+}
+
 } // namespace WebKit
diff --git a/Source/WebKit/UIProcess/wpe/InspectorTargetProxyWPE.cpp b/Source/WebKit/UIProcess/wpe/InspectorTargetProxyWPE.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..7453194ca6f032ba86a4c67f5bf12688ab6ec1be
--- /dev/null
+++ b/Source/WebKit/UIProcess/wpe/InspectorTargetProxyWPE.cpp
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "InspectorTargetProxy.h"
+
+#include "WebPageProxy.h"
+#include <wpe/wpe.h>
+
+namespace WebKit {
+
+void InspectorTargetProxy::platformActivate(String& error) const
+{
+    struct wpe_view_backend* backend = m_page.viewBackend();
+    wpe_view_backend_add_activity_state(backend, wpe_view_activity_state_visible | wpe_view_activity_state_focused | wpe_view_activity_state_in_window);
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/wpe/WebPageInspectorEmulationAgentWPE.cpp b/Source/WebKit/UIProcess/wpe/WebPageInspectorEmulationAgentWPE.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5dc76aa302cb574307059e66a1b73730efe920da
--- /dev/null
+++ b/Source/WebKit/UIProcess/wpe/WebPageInspectorEmulationAgentWPE.cpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "WebPageInspectorEmulationAgent.h"
+
+#include "WebPageProxy.h"
+#include <wpe/wpe.h>
+
+namespace WebKit {
+
+void WebPageInspectorEmulationAgent::platformSetSize(int width, int height, Function<void (const String& error)>&& callback)
+{
+    struct wpe_view_backend* backend = m_page.viewBackend();
+    wpe_view_backend_dispatch_set_size(backend, width, height);
+    callback(String());
+}
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/wpe/WebPageInspectorInputAgentWPE.cpp b/Source/WebKit/UIProcess/wpe/WebPageInspectorInputAgentWPE.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..585fb151f302e4b376c705ed0d0974d518733605
--- /dev/null
+++ b/Source/WebKit/UIProcess/wpe/WebPageInspectorInputAgentWPE.cpp
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2019 Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "WebPageInspectorInputAgent.h"
+
+#include "NativeWebKeyboardEvent.h"
+#include "WebPageProxy.h"
+#include <WebCore/PlatformKeyboardEvent.h>
+#include <wpe/wpe.h>
+
+namespace WebKit {
+
+void WebPageInspectorInputAgent::platformDispatchKeyEvent(WebKeyboardEvent::Type type, const String& text, const String& unmodifiedText, const String& key, const String& code, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<WebEvent::Modifier> modifiers, Vector<String>& macCommands, WallTime timestamp)
+{
+    unsigned keyCode = WebCore::PlatformKeyboardEvent::WPEKeyCodeForWindowsKeyCode(windowsVirtualKeyCode);
+    String keyIdentifier;
+    if (keyCode)
+        keyIdentifier = WebCore::PlatformKeyboardEvent::keyIdentifierForWPEKeyCode(keyCode);
+    NativeWebKeyboardEvent event(
+        type,
+        text,
+        unmodifiedText,
+        key,
+        code,
+        keyIdentifier,
+        windowsVirtualKeyCode,
+        nativeVirtualKeyCode,
+        isAutoRepeat,
+        isKeypad,
+        isSystemKey,
+        modifiers,
+        timestamp);
+    m_page.handleKeyboardEvent(event);
+}
+ 
+} // namespace WebKit
diff --git a/Source/WebKit/WebKit.xcodeproj/project.pbxproj b/Source/WebKit/WebKit.xcodeproj/project.pbxproj
index 2ccfb65a84a27cfbe765bf75b916c653123f6324..38c585ad7fff7b42b96817fe7292aba01ecfa85e 100644
--- a/Source/WebKit/WebKit.xcodeproj/project.pbxproj
+++ b/Source/WebKit/WebKit.xcodeproj/project.pbxproj
@@ -1731,6 +1731,19 @@
 		CEE4AE2B1A5DCF430002F49B /* UIKitSPI.h in Headers */ = {isa = PBXBuildFile; fileRef = CEE4AE2A1A5DCF430002F49B /* UIKitSPI.h */; };
 		D3B9484711FF4B6500032B39 /* WebPopupMenu.h in Headers */ = {isa = PBXBuildFile; fileRef = D3B9484311FF4B6500032B39 /* WebPopupMenu.h */; };
 		D3B9484911FF4B6500032B39 /* WebSearchPopupMenu.h in Headers */ = {isa = PBXBuildFile; fileRef = D3B9484511FF4B6500032B39 /* WebSearchPopupMenu.h */; };
+		D71A94322370E025002C4D9E /* InspectorBrowserAgentClientMac.h in Headers */ = {isa = PBXBuildFile; fileRef = D71A94302370E025002C4D9E /* InspectorBrowserAgentClientMac.h */; };
+		D71A94342370E07A002C4D9E /* InspectorBrowserAgentClient.h in Headers */ = {isa = PBXBuildFile; fileRef = D71A94332370E07A002C4D9E /* InspectorBrowserAgentClient.h */; };
+		D71A94382370F032002C4D9E /* BrowserInspectorController.h in Headers */ = {isa = PBXBuildFile; fileRef = D71A94372370F032002C4D9E /* BrowserInspectorController.h */; };
+		D71A943A2370F061002C4D9E /* RemoteInspectorPipe.h in Headers */ = {isa = PBXBuildFile; fileRef = D71A94392370F060002C4D9E /* RemoteInspectorPipe.h */; };
+		D71A94422371F67E002C4D9E /* WebPageInspectorEmulationAgent.h in Headers */ = {isa = PBXBuildFile; fileRef = D71A943F2371F67E002C4D9E /* WebPageInspectorEmulationAgent.h */; };
+		D71A94432371F67E002C4D9E /* WebPageInspectorInputAgent.h in Headers */ = {isa = PBXBuildFile; fileRef = D71A94402371F67E002C4D9E /* WebPageInspectorInputAgent.h */; };
+		D71A944A2372290B002C4D9E /* _WKBrowserInspector.h in Headers */ = {isa = PBXBuildFile; fileRef = D71A94492372290B002C4D9E /* _WKBrowserInspector.h */; settings = {ATTRIBUTES = (Private, ); }; };
+		D71A944C237239FB002C4D9E /* BrowserInspectorPipe.h in Headers */ = {isa = PBXBuildFile; fileRef = D71A944B237239FB002C4D9E /* BrowserInspectorPipe.h */; };
+		D76D6888238DBD81008D314B /* InspectorDialogAgent.h in Headers */ = {isa = PBXBuildFile; fileRef = D76D6887238DBD80008D314B /* InspectorDialogAgent.h */; };
+		D79902B1236E9404005D6F7E /* WebPageInspectorEmulationAgentMac.mm in Sources */ = {isa = PBXBuildFile; fileRef = D79902AE236E9404005D6F7E /* WebPageInspectorEmulationAgentMac.mm */; };
+		D79902B2236E9404005D6F7E /* InspectorTargetProxyMac.mm in Sources */ = {isa = PBXBuildFile; fileRef = D79902AF236E9404005D6F7E /* InspectorTargetProxyMac.mm */; };
+		D79902B3236E9404005D6F7E /* WebPageInspectorInputAgentMac.mm in Sources */ = {isa = PBXBuildFile; fileRef = D79902B0236E9404005D6F7E /* WebPageInspectorInputAgentMac.mm */; };
+		D7EB04E72372A73B00F744CE /* InspectorBrowserAgentClientMac.mm in Sources */ = {isa = PBXBuildFile; fileRef = D7EB04E62372A73B00F744CE /* InspectorBrowserAgentClientMac.mm */; };
 		DF462E0F23F22F5500EFF35F /* WKHTTPCookieStorePrivate.h in Headers */ = {isa = PBXBuildFile; fileRef = DF462E0E23F22F5300EFF35F /* WKHTTPCookieStorePrivate.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		DF462E1223F338BE00EFF35F /* WKContentWorldPrivate.h in Headers */ = {isa = PBXBuildFile; fileRef = DF462E1123F338AD00EFF35F /* WKContentWorldPrivate.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		E105FE5418D7B9DE008F57A8 /* EditingRange.h in Headers */ = {isa = PBXBuildFile; fileRef = E105FE5318D7B9DE008F57A8 /* EditingRange.h */; };
@@ -5012,6 +5025,20 @@
 		D3B9484311FF4B6500032B39 /* WebPopupMenu.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WebPopupMenu.h; sourceTree = "<group>"; };
 		D3B9484411FF4B6500032B39 /* WebSearchPopupMenu.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = WebSearchPopupMenu.cpp; sourceTree = "<group>"; };
 		D3B9484511FF4B6500032B39 /* WebSearchPopupMenu.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WebSearchPopupMenu.h; sourceTree = "<group>"; };
+		D71A942C2370DF81002C4D9E /* WKBrowserInspector.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WKBrowserInspector.h; sourceTree = "<group>"; };
+		D71A94302370E025002C4D9E /* InspectorBrowserAgentClientMac.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = InspectorBrowserAgentClientMac.h; sourceTree = "<group>"; };
+		D71A94332370E07A002C4D9E /* InspectorBrowserAgentClient.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = InspectorBrowserAgentClient.h; sourceTree = "<group>"; };
+		D71A94372370F032002C4D9E /* BrowserInspectorController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = BrowserInspectorController.h; sourceTree = "<group>"; };
+		D71A94392370F060002C4D9E /* RemoteInspectorPipe.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = RemoteInspectorPipe.h; sourceTree = "<group>"; };
+		D71A943F2371F67E002C4D9E /* WebPageInspectorEmulationAgent.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WebPageInspectorEmulationAgent.h; sourceTree = "<group>"; };
+		D71A94402371F67E002C4D9E /* WebPageInspectorInputAgent.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WebPageInspectorInputAgent.h; sourceTree = "<group>"; };
+		D71A94492372290B002C4D9E /* _WKBrowserInspector.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = _WKBrowserInspector.h; sourceTree = "<group>"; };
+		D71A944B237239FB002C4D9E /* BrowserInspectorPipe.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = BrowserInspectorPipe.h; sourceTree = "<group>"; };
+		D76D6887238DBD80008D314B /* InspectorDialogAgent.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = InspectorDialogAgent.h; sourceTree = "<group>"; };
+		D79902AE236E9404005D6F7E /* WebPageInspectorEmulationAgentMac.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = WebPageInspectorEmulationAgentMac.mm; sourceTree = "<group>"; };
+		D79902AF236E9404005D6F7E /* InspectorTargetProxyMac.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = InspectorTargetProxyMac.mm; sourceTree = "<group>"; };
+		D79902B0236E9404005D6F7E /* WebPageInspectorInputAgentMac.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = WebPageInspectorInputAgentMac.mm; sourceTree = "<group>"; };
+		D7EB04E62372A73B00F744CE /* InspectorBrowserAgentClientMac.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = InspectorBrowserAgentClientMac.mm; sourceTree = "<group>"; };
 		DF462E0E23F22F5300EFF35F /* WKHTTPCookieStorePrivate.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WKHTTPCookieStorePrivate.h; sourceTree = "<group>"; };
 		DF462E1123F338AD00EFF35F /* WKContentWorldPrivate.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WKContentWorldPrivate.h; sourceTree = "<group>"; };
 		DF58C6311371AC5800F9A37C /* NativeWebWheelEvent.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = NativeWebWheelEvent.h; sourceTree = "<group>"; };
@@ -6850,6 +6877,7 @@
 		37C4C08318149C2A003688B9 /* Cocoa */ = {
 			isa = PBXGroup;
 			children = (
+				D71A94492372290B002C4D9E /* _WKBrowserInspector.h */,
 				1A43E826188F38E2009E4D30 /* Deprecated */,
 				37A5E01218BBF937000A081E /* _WKActivatedElementInfo.h */,
 				37A5E01118BBF937000A081E /* _WKActivatedElementInfo.mm */,
@@ -8490,6 +8518,13 @@
 		BC032DC310F438260058C15A /* UIProcess */ = {
 			isa = PBXGroup;
 			children = (
+				D76D6887238DBD80008D314B /* InspectorDialogAgent.h */,
+				D71A944B237239FB002C4D9E /* BrowserInspectorPipe.h */,
+				D71A943F2371F67E002C4D9E /* WebPageInspectorEmulationAgent.h */,
+				D71A94402371F67E002C4D9E /* WebPageInspectorInputAgent.h */,
+				D71A94392370F060002C4D9E /* RemoteInspectorPipe.h */,
+				D71A94372370F032002C4D9E /* BrowserInspectorController.h */,
+				D71A94332370E07A002C4D9E /* InspectorBrowserAgentClient.h */,
 				BC032DC410F4387C0058C15A /* API */,
 				512F588D12A8836F00629530 /* Authentication */,
 				9955A6E81C79809000EB6A93 /* Automation */,
@@ -8768,6 +8803,7 @@
 		BC0C376610F807660076D7CB /* C */ = {
 			isa = PBXGroup;
 			children = (
+				D71A942C2370DF81002C4D9E /* WKBrowserInspector.h */,
 				5123CF18133D25E60056F800 /* cg */,
 				6EE849C41368D9040038D481 /* mac */,
 				BCB63477116BF10600603215 /* WebKit2_C.h */,
@@ -9370,6 +9406,11 @@
 		BCCF085C113F3B7500C650C5 /* mac */ = {
 			isa = PBXGroup;
 			children = (
+				D7EB04E62372A73B00F744CE /* InspectorBrowserAgentClientMac.mm */,
+				D71A94302370E025002C4D9E /* InspectorBrowserAgentClientMac.h */,
+				D79902AE236E9404005D6F7E /* WebPageInspectorEmulationAgentMac.mm */,
+				D79902B0236E9404005D6F7E /* WebPageInspectorInputAgentMac.mm */,
+				D79902AF236E9404005D6F7E /* InspectorTargetProxyMac.mm */,
 				B878B613133428DC006888E9 /* CorrectionPanel.h */,
 				B878B614133428DC006888E9 /* CorrectionPanel.mm */,
 				C1817362205844A900DFDA65 /* DisplayLink.cpp */,
@@ -10065,6 +10106,7 @@
 				5CAFDE452130846300B1F7E1 /* _WKInspector.h in Headers */,
 				991F492F23A812C60054642B /* _WKInspectorDebuggableInfo.h in Headers */,
 				99036AE223A949CF0000B06A /* _WKInspectorDebuggableInfoInternal.h in Headers */,
+				D71A944A2372290B002C4D9E /* _WKBrowserInspector.h in Headers */,
 				5CAFDE472130846A00B1F7E1 /* _WKInspectorInternal.h in Headers */,
 				9979CA58237F49F10039EC05 /* _WKInspectorPrivate.h in Headers */,
 				A5C0F0AB2000658200536536 /* _WKInspectorWindow.h in Headers */,
@@ -10188,6 +10230,7 @@
 				7C89D2981A6753B2003A5FDE /* APIPageConfiguration.h in Headers */,
 				1AC1336C18565C7A00F3EC05 /* APIPageHandle.h in Headers */,
 				1AFDD3151891B54000153970 /* APIPolicyClient.h in Headers */,
+				D71A94382370F032002C4D9E /* BrowserInspectorController.h in Headers */,
 				7CE4D2201A4914CA00C7F152 /* APIProcessPoolConfiguration.h in Headers */,
 				49BCA19223A177660028A836 /* APIResourceLoadStatisticsFirstParty.h in Headers */,
 				49BCA19723A1930D0028A836 /* APIResourceLoadStatisticsThirdParty.h in Headers */,
@@ -10313,6 +10356,7 @@
 				BC06F43A12DBCCFB002D78DE /* GeolocationPermissionRequestProxy.h in Headers */,
 				2DA944A41884E4F000ED86DB /* GestureTypes.h in Headers */,
 				2DA049B8180CCD0A00AAFA9E /* GraphicsLayerCARemote.h in Headers */,
+				D71A94342370E07A002C4D9E /* InspectorBrowserAgentClient.h in Headers */,
 				C0CE72AD1247E78D00BC0EC4 /* HandleMessage.h in Headers */,
 				1AC75A1B1B3368270056745B /* HangDetectionDisabler.h in Headers */,
 				57AC8F50217FEED90055438C /* HidConnection.h in Headers */,
@@ -10436,8 +10480,10 @@
 				41DC45961E3D6E2200B11F51 /* NetworkRTCProvider.h in Headers */,
 				413075AB1DE85F330039EC69 /* NetworkRTCSocket.h in Headers */,
 				5C20CBA01BB1ECD800895BB1 /* NetworkSession.h in Headers */,
+				D71A94422371F67E002C4D9E /* WebPageInspectorEmulationAgent.h in Headers */,
 				532159551DBAE7290054AA3C /* NetworkSessionCocoa.h in Headers */,
 				417915B92257046F00D6F97E /* NetworkSocketChannel.h in Headers */,
+				D71A943A2370F061002C4D9E /* RemoteInspectorPipe.h in Headers */,
 				570DAAC22303730300E8FC04 /* NfcConnection.h in Headers */,
 				570DAAAE23026F5C00E8FC04 /* NfcService.h in Headers */,
 				31A2EC5614899C0900810D71 /* NotificationPermissionRequest.h in Headers */,
@@ -10521,6 +10567,7 @@
 				CD2865EE2255562000606AC7 /* ProcessTaskStateObserver.h in Headers */,
 				463FD4821EB94EC000A2982C /* ProcessTerminationReason.h in Headers */,
 				86E67A251910B9D100004AB7 /* ProcessThrottler.h in Headers */,
+				D71A944C237239FB002C4D9E /* BrowserInspectorPipe.h in Headers */,
 				83048AE61ACA45DC0082C832 /* ProcessThrottlerClient.h in Headers */,
 				A1E688701F6E2BAB007006A6 /* QuarantineSPI.h in Headers */,
 				57FD318222B3515E008D0E8B /* RedirectSOAuthorizationSession.h in Headers */,
@@ -10932,6 +10979,7 @@
 				BCD25F1711D6BDE100169B0E /* WKBundleFrame.h in Headers */,
 				BCF049E611FE20F600F86A58 /* WKBundleFramePrivate.h in Headers */,
 				BC49862F124D18C100D834E1 /* WKBundleHitTestResult.h in Headers */,
+				D71A94432371F67E002C4D9E /* WebPageInspectorInputAgent.h in Headers */,
 				BC204EF211C83EC8008F3375 /* WKBundleInitialize.h in Headers */,
 				65B86F1E12F11DE300B7DD8A /* WKBundleInspector.h in Headers */,
 				1A8B66B41BC45B010082DF77 /* WKBundleMac.h in Headers */,
@@ -10984,6 +11032,7 @@
 				5C795D71229F3757003FF1C4 /* WKContextMenuElementInfoPrivate.h in Headers */,
 				51A555F6128C6C47009ABCEC /* WKContextMenuItem.h in Headers */,
 				51A55601128C6D92009ABCEC /* WKContextMenuItemTypes.h in Headers */,
+				D76D6888238DBD81008D314B /* InspectorDialogAgent.h in Headers */,
 				A1EA02381DABFF7E0096021F /* WKContextMenuListener.h in Headers */,
 				BCC938E11180DE440085E5FE /* WKContextPrivate.h in Headers */,
 				9FB5F395169E6A80002C25BF /* WKContextPrivateMac.h in Headers */,
@@ -11134,6 +11183,7 @@
 				1AB8A1F818400BB800E9AE69 /* WKPageContextMenuClient.h in Headers */,
 				8372DB251A674C8F00C697C5 /* WKPageDiagnosticLoggingClient.h in Headers */,
 				1AB8A1F418400B8F00E9AE69 /* WKPageFindClient.h in Headers */,
+				D71A94322370E025002C4D9E /* InspectorBrowserAgentClientMac.h in Headers */,
 				1AB8A1F618400B9D00E9AE69 /* WKPageFindMatchesClient.h in Headers */,
 				1AB8A1F018400B0000E9AE69 /* WKPageFormClient.h in Headers */,
 				BC7B633712A45ABA00D174A4 /* WKPageGroup.h in Headers */,
@@ -12159,6 +12209,7 @@
 				CDA93DB122F8BCF400490A69 /* FullscreenTouchSecheuristicParameters.cpp in Sources */,
 				2749F6442146561B008380BF /* InjectedBundleNodeHandle.cpp in Sources */,
 				2749F6452146561E008380BF /* InjectedBundleRangeHandle.cpp in Sources */,
+				D79902B2236E9404005D6F7E /* InspectorTargetProxyMac.mm in Sources */,
 				2D913441212CF9F000128AFD /* JSNPMethod.cpp in Sources */,
 				2D913442212CF9F000128AFD /* JSNPObject.cpp in Sources */,
 				2984F588164BA095004BC0C6 /* LegacyCustomProtocolManagerMessageReceiver.cpp in Sources */,
@@ -12169,6 +12220,7 @@
 				2D92A781212B6A7100F493FD /* MessageReceiverMap.cpp in Sources */,
 				2D92A782212B6A7100F493FD /* MessageSender.cpp in Sources */,
 				2D92A77A212B6A6100F493FD /* Module.cpp in Sources */,
+				D79902B1236E9404005D6F7E /* WebPageInspectorEmulationAgentMac.mm in Sources */,
 				57B826452304F14000B72EB0 /* NearFieldSoftLink.mm in Sources */,
 				2D913443212CF9F000128AFD /* NetscapeBrowserFuncs.cpp in Sources */,
 				2D913444212CF9F000128AFD /* NetscapePlugin.cpp in Sources */,
@@ -12193,6 +12245,7 @@
 				1A2D8439127F65D5001EB962 /* NPObjectMessageReceiverMessageReceiver.cpp in Sources */,
 				2D92A792212B6AD400F493FD /* NPObjectProxy.cpp in Sources */,
 				2D92A793212B6AD400F493FD /* NPRemoteObjectMap.cpp in Sources */,
+				D7EB04E72372A73B00F744CE /* InspectorBrowserAgentClientMac.mm in Sources */,
 				2D913447212CF9F000128AFD /* NPRuntimeObjectMap.cpp in Sources */,
 				2D913448212CF9F000128AFD /* NPRuntimeUtilities.cpp in Sources */,
 				2D92A794212B6AD400F493FD /* NPVariantData.cpp in Sources */,
@@ -12463,6 +12516,7 @@
 				2D92A78C212B6AB100F493FD /* WebMouseEvent.cpp in Sources */,
 				31BA924D148831260062EDB5 /* WebNotificationManagerMessageReceiver.cpp in Sources */,
 				2DF6FE52212E110900469030 /* WebPage.cpp in Sources */,
+				D79902B3236E9404005D6F7E /* WebPageInspectorInputAgentMac.mm in Sources */,
 				C0CE72A01247E71D00BC0EC4 /* WebPageMessageReceiver.cpp in Sources */,
 				BCBD3914125BB1A800D2C29F /* WebPageProxyMessageReceiver.cpp in Sources */,
 				7CE9CE101FA0767A000177DE /* WebPageUpdatePreferences.cpp in Sources */,
diff --git a/Source/WebKit/WebProcess/Network/WebLoaderStrategy.cpp b/Source/WebKit/WebProcess/Network/WebLoaderStrategy.cpp
index 7357f54d95cf1224be46ce3da3237a8cabbf1ef3..df886217c38e30014350a75467d7c140839da63f 100644
--- a/Source/WebKit/WebProcess/Network/WebLoaderStrategy.cpp
+++ b/Source/WebKit/WebProcess/Network/WebLoaderStrategy.cpp
@@ -58,6 +58,7 @@
 #include <WebCore/Frame.h>
 #include <WebCore/FrameLoader.h>
 #include <WebCore/HTMLFrameOwnerElement.h>
+#include <WebCore/InspectorInstrumentationWebKit.h>
 #include <WebCore/NetscapePlugInStreamLoader.h>
 #include <WebCore/NetworkLoadInformation.h>
 #include <WebCore/PlatformStrategies.h>
@@ -228,8 +229,24 @@ void WebLoaderStrategy::scheduleLoad(ResourceLoader& resourceLoader, CachedResou
     }
 #endif
 
+    if (m_emulateOfflineState) {
+        scheduleInternallyFailedLoad(resourceLoader);
+        return;
+    }
+
     if (!tryLoadingUsingURLSchemeHandler(resourceLoader, trackingParameters)) {
         WEBLOADERSTRATEGY_RELEASE_LOG_IF_ALLOWED("scheduleLoad: URL will be scheduled with the NetworkProcess");
+
+        RefPtr<ResourceLoader> coreLoader = &resourceLoader;
+        if (!resourceLoader.options().serviceWorkerRegistrationIdentifier) {
+            if (InspectorInstrumentationWebKit::interceptRequest(resourceLoader, [this, coreLoader, trackingParameters, shouldClearReferrerOnHTTPSToHTTPRedirect, resource](bool handled) mutable {
+                    if (!handled)
+                        scheduleLoadFromNetworkProcess(*coreLoader, coreLoader->request(), trackingParameters, shouldClearReferrerOnHTTPSToHTTPRedirect, maximumBufferingTime(resource));
+                    })) {
+                return;
+            }
+        }
+
         scheduleLoadFromNetworkProcess(resourceLoader, resourceLoader.request(), trackingParameters, shouldClearReferrerOnHTTPSToHTTPRedirect, maximumBufferingTime(resource));
         return;
     }
@@ -765,7 +782,7 @@ void WebLoaderStrategy::didFinishPreconnection(uint64_t preconnectionIdentifier,
 
 bool WebLoaderStrategy::isOnLine() const
 {
-    return m_isOnLine;
+    return m_emulateOfflineState ? false : m_isOnLine;
 }
 
 void WebLoaderStrategy::addOnlineStateChangeListener(Function<void(bool)>&& listener)
@@ -776,6 +793,11 @@ void WebLoaderStrategy::addOnlineStateChangeListener(Function<void(bool)>&& list
 
 void WebLoaderStrategy::setOnLineState(bool isOnLine)
 {
+    if (m_emulateOfflineState) {
+        m_isOnLine = isOnLine;
+        return;
+    }
+
     if (m_isOnLine == isOnLine)
         return;
 
@@ -784,6 +806,12 @@ void WebLoaderStrategy::setOnLineState(bool isOnLine)
         listener(isOnLine);
 }
 
+void WebLoaderStrategy::setEmulateOfflineState(bool offline) {
+    m_emulateOfflineState = offline;
+    for (auto& listener : m_onlineStateChangeListeners)
+        listener(offline ? false : m_isOnLine);
+}
+
 void WebLoaderStrategy::setCaptureExtraNetworkLoadMetricsEnabled(bool enabled)
 {
     WebProcess::singleton().ensureNetworkProcessConnection().connection().send(Messages::NetworkConnectionToWebProcess::SetCaptureExtraNetworkLoadMetricsEnabled(enabled), 0);
diff --git a/Source/WebKit/WebProcess/Network/WebLoaderStrategy.h b/Source/WebKit/WebProcess/Network/WebLoaderStrategy.h
index 9a78a5fe24da78b34ebefa785a07b5049ba473ba..17f4f626641629cb6c97d36b7361305a1f5d8258 100644
--- a/Source/WebKit/WebProcess/Network/WebLoaderStrategy.h
+++ b/Source/WebKit/WebProcess/Network/WebLoaderStrategy.h
@@ -87,6 +87,7 @@ public:
     bool isOnLine() const final;
     void addOnlineStateChangeListener(Function<void(bool)>&&) final;
     void setOnLineState(bool);
+    void setEmulateOfflineState(bool) final;
 
 private:
     void scheduleLoad(WebCore::ResourceLoader&, WebCore::CachedResource*, bool shouldClearReferrerOnHTTPSToHTTPRedirect);
@@ -125,6 +126,7 @@ private:
     HashMap<unsigned long, PreconnectCompletionHandler> m_preconnectCompletionHandlers;
     Vector<Function<void(bool)>> m_onlineStateChangeListeners;
     bool m_isOnLine { true };
+    bool m_emulateOfflineState { false };
     HashSet<WebResourceLoader*> m_loadersWithUploads;
 };
 
diff --git a/Source/WebKit/WebProcess/WebCoreSupport/WebChromeClient.cpp b/Source/WebKit/WebProcess/WebCoreSupport/WebChromeClient.cpp
index 77bc5dd4909e8672ea202e753b503382f6834bf4..7f2175a73b9985ba2d29b5c6707f9c9da3b8b2f6 100644
--- a/Source/WebKit/WebProcess/WebCoreSupport/WebChromeClient.cpp
+++ b/Source/WebKit/WebProcess/WebCoreSupport/WebChromeClient.cpp
@@ -409,6 +409,8 @@ void WebChromeClient::setResizable(bool resizable)
 
 void WebChromeClient::addMessageToConsole(MessageSource source, MessageLevel level, const String& message, unsigned lineNumber, unsigned columnNumber, const String& sourceID)
 {
+    if (level == MessageLevel::Error)
+        m_page.send(Messages::WebPageProxy::LogToStderr(message));
     // Notify the bundle client.
     m_page.injectedBundleUIClient().willAddMessageToConsole(&m_page, source, level, message, lineNumber, columnNumber, sourceID);
 }
diff --git a/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp b/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp
index 2c1a3362304c0aab9eccca58c3fe67b7250d2232..bde6a8e7b76eaa367aeba99489c06e46419890be 100644
--- a/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp
+++ b/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp
@@ -244,12 +244,20 @@ void DrawingAreaCoordinatedGraphics::updatePreferences(const WebPreferencesStore
         settings.setAcceleratedCompositingEnabled(false);
     }
 #endif
+
+#if USE(LIBWPE)
+    settings.setAcceleratedCompositingEnabled(false);
+    settings.setForceCompositingMode(false);
+    settings.setAcceleratedCompositingForFixedPositionEnabled(false);
+    m_alwaysUseCompositing = false;
+#else
     settings.setForceCompositingMode(store.getBoolValueForKey(WebPreferencesKey::forceCompositingModeKey()));
     // Fixed position elements need to be composited and create stacking contexts
     // in order to be scrolled by the ScrollingCoordinator.
     settings.setAcceleratedCompositingForFixedPositionEnabled(settings.acceleratedCompositingEnabled());
 
     m_alwaysUseCompositing = settings.acceleratedCompositingEnabled() && settings.forceCompositingMode();
+#endif
 
     // If async scrolling is disabled, we have to force-disable async frame and overflow scrolling
     // to keep the non-async scrolling on those elements working.
diff --git a/Source/WebKit/WebProcess/WebPage/WebDocumentLoader.cpp b/Source/WebKit/WebProcess/WebPage/WebDocumentLoader.cpp
index b2d54a627b94583bda3518c4e7c3364481b605a4..d407e32b6a7b8b27925c49391e86d42c9b3dfa8b 100644
--- a/Source/WebKit/WebProcess/WebPage/WebDocumentLoader.cpp
+++ b/Source/WebKit/WebProcess/WebPage/WebDocumentLoader.cpp
@@ -47,6 +47,14 @@ void WebDocumentLoader::detachFromFrame()
     DocumentLoader::detachFromFrame();
 }
 
+void WebDocumentLoader::replacedByFragmentNavigation(Frame& frame)
+{
+    ASSERT(!this->frame());
+    // Notify WebPageProxy that the navigation has been converted into same page navigation.
+    if (m_navigationID)
+        WebFrame::fromCoreFrame(frame)->documentLoaderDetached(m_navigationID);
+}
+
 void WebDocumentLoader::setNavigationID(uint64_t navigationID)
 {
     ASSERT(navigationID);
diff --git a/Source/WebKit/WebProcess/WebPage/WebDocumentLoader.h b/Source/WebKit/WebProcess/WebPage/WebDocumentLoader.h
index f127d64d005ab7b93875591b94a5899205e91579..df0de26e4dc449a0fbf93e7037444df4e5365822 100644
--- a/Source/WebKit/WebProcess/WebPage/WebDocumentLoader.h
+++ b/Source/WebKit/WebProcess/WebPage/WebDocumentLoader.h
@@ -43,7 +43,10 @@ public:
 private:
     WebDocumentLoader(const WebCore::ResourceRequest&, const WebCore::SubstituteData&);
 
+    uint64_t loaderIDForInspector() override { return navigationID(); }
+
     void detachFromFrame() override;
+    void replacedByFragmentNavigation(WebCore::Frame&) override;
 
     uint64_t m_navigationID;
 };
diff --git a/Source/WebKit/WebProcess/WebPage/WebPage.cpp b/Source/WebKit/WebProcess/WebPage/WebPage.cpp
index b9264a98fcd016d013aabcffbfd18d8b4f21678c..3e75762e13535f9c457b8ef8ddc3dbe81db6fa02 100644
--- a/Source/WebKit/WebProcess/WebPage/WebPage.cpp
+++ b/Source/WebKit/WebProcess/WebPage/WebPage.cpp
@@ -730,6 +730,9 @@ WebPage::WebPage(PageIdentifier pageID, WebPageCreationParameters&& parameters)
     send(Messages::WebPageProxy::DidCreateContextForVisibilityPropagation(m_contextForVisibilityPropagation->contextID()));
 #endif
 
+    if (parameters.shouldPauseInInspectorWhenShown)
+        m_page->inspectorController().pauseWhenShown();
+
     updateThrottleState();
 }
 
@@ -1568,6 +1571,22 @@ void WebPage::platformDidReceiveLoadParameters(const LoadParameters& loadParamet
 }
 #endif
 
+void WebPage::loadRequestInFrameForInspector(LoadParameters&& loadParameters, WebCore::FrameIdentifier frameID)
+{
+    WebFrame* frame = WebProcess::singleton().webFrame(frameID);
+    if (!frame) {
+        send(Messages::WebPageProxy::DidDestroyNavigation(loadParameters.navigationID));
+        return;
+    }
+
+    // FIXME: use m_pendingNavigationID instead?
+    m_pendingFrameNavigationID = loadParameters.navigationID;
+
+    FrameLoadRequest frameLoadRequest { *frame->coreFrame(), loadParameters.request, ShouldOpenExternalURLsPolicy::ShouldNotAllow };
+    frame->coreFrame()->loader().load(WTFMove(frameLoadRequest));
+    ASSERT(!m_pendingFrameNavigationID);
+}
+
 void WebPage::loadRequest(LoadParameters&& loadParameters)
 {
     setIsNavigatingToAppBoundDomain(loadParameters.isNavigatingToAppBoundDomain);
@@ -1751,17 +1770,13 @@ void WebPage::setSize(const WebCore::IntSize& viewSize)
     view->resize(viewSize);
     m_drawingArea->setNeedsDisplay();
 
-#if USE(COORDINATED_GRAPHICS)
     if (view->useFixedLayout())
         sendViewportAttributesChanged(m_page->viewportArguments());
-#endif
 }
 
-#if USE(COORDINATED_GRAPHICS)
 void WebPage::sendViewportAttributesChanged(const ViewportArguments& viewportArguments)
 {
-    FrameView* view = m_page->mainFrame().view();
-    ASSERT(view && view->useFixedLayout());
+    ASSERT(m_page->mainFrame().view() && m_page->mainFrame().view()->useFixedLayout());
 
     // Viewport properties have no impact on zero sized fixed viewports.
     if (m_viewSize.isEmpty())
@@ -1778,20 +1793,18 @@ void WebPage::sendViewportAttributesChanged(const ViewportArguments& viewportArg
 
     ViewportAttributes attr = computeViewportAttributes(viewportArguments, minimumLayoutFallbackWidth, deviceWidth, deviceHeight, 1, m_viewSize);
 
-    // If no layout was done yet set contentFixedOrigin to (0,0).
-    IntPoint contentFixedOrigin = view->didFirstLayout() ? view->fixedVisibleContentRect().location() : IntPoint();
-
-    // Put the width and height to the viewport width and height. In css units however.
-    // Use FloatSize to avoid truncated values during scale.
-    FloatSize contentFixedSize = m_viewSize;
-
-    contentFixedSize.scale(1 / attr.initialScale);
-    view->setFixedVisibleContentRect(IntRect(contentFixedOrigin, roundedIntSize(contentFixedSize)));
+#if ENABLE(CSS_DEVICE_ADAPTATION)
+    FrameView* view = m_page->mainFrame().view();
+    // CSS viewport descriptors might be applied to already affected viewport size
+    // if the page enables/disables stylesheets, so need to keep initial viewport size.
+    view->setInitialViewportSize(roundedIntSize(m_viewSize));
+#endif
 
     attr.initialScale = m_page->viewportArguments().zoom; // Resets auto (-1) if no value was set by user.
 
     // This also takes care of the relayout.
     setFixedLayoutSize(roundedIntSize(attr.layoutSize));
+    scaleView(deviceWidth / attr.layoutSize.width());
 
 #if USE(COORDINATED_GRAPHICS)
     m_drawingArea->didChangeViewportAttributes(WTFMove(attr));
@@ -1799,7 +1812,6 @@ void WebPage::sendViewportAttributesChanged(const ViewportArguments& viewportArg
     send(Messages::WebPageProxy::DidChangeViewportProperties(attr));
 #endif
 }
-#endif
 
 void WebPage::scrollMainFrameIfNotAtMaxScrollPosition(const IntSize& scrollOffset)
 {
@@ -2081,6 +2093,7 @@ void WebPage::scaleView(double scale)
     }
 
     m_page->setViewScaleFactor(scale);
+    send(Messages::WebPageProxy::ViewScaleFactorDidChange(scale));
     scalePage(pageScale, scrollPositionAtNewScale);
 }
 
@@ -2185,17 +2198,13 @@ void WebPage::viewportPropertiesDidChange(const ViewportArguments& viewportArgum
         viewportConfigurationChanged();
 #endif
 
-#if USE(COORDINATED_GRAPHICS)
     FrameView* view = m_page->mainFrame().view();
     if (view && view->useFixedLayout())
         sendViewportAttributesChanged(viewportArguments);
+#if USE(COORDINATED_GRAPHICS)
     else
         m_drawingArea->didChangeViewportAttributes(ViewportAttributes());
 #endif
-
-#if !PLATFORM(IOS_FAMILY) && !USE(COORDINATED_GRAPHICS)
-    UNUSED_PARAM(viewportArguments);
-#endif
 }
 
 void WebPage::listenForLayoutMilestones(OptionSet<WebCore::LayoutMilestone> milestones)
@@ -3081,6 +3090,11 @@ void WebPage::sendMessageToTargetBackend(const String& targetId, const String& m
     m_inspectorTargetController->sendMessageToTargetBackend(targetId, message);
 }
 
+void WebPage::resumeInspectorIfPausedInNewWindow()
+{
+    m_page->inspectorController().resumeIfPausedInNewWindow();
+}
+
 void WebPage::insertNewlineInQuotedContent()
 {
     Frame& frame = m_page->focusController().focusedOrMainFrame();
@@ -3325,6 +3339,7 @@ void WebPage::didCompletePageTransition()
 void WebPage::show()
 {
     send(Messages::WebPageProxy::ShowPage());
+    m_page->inspectorController().didShowNewWindow();
 }
 
 String WebPage::userAgent(const URL& webCoreURL) const
@@ -6324,6 +6339,9 @@ Ref<DocumentLoader> WebPage::createDocumentLoader(Frame& frame, const ResourceRe
             WebsitePoliciesData::applyToDocumentLoader(WTFMove(*m_pendingWebsitePolicies), documentLoader);
             m_pendingWebsitePolicies = WTF::nullopt;
         }
+    } else if (m_pendingFrameNavigationID) {
+        documentLoader->setNavigationID(m_pendingFrameNavigationID);
+        m_pendingFrameNavigationID = 0;
     }
 
     return documentLoader;
diff --git a/Source/WebKit/WebProcess/WebPage/WebPage.h b/Source/WebKit/WebProcess/WebPage/WebPage.h
index fd741eb78d319edcbb53cbc811443b61dfc19424..01e4ec4b6586620323f3f6e11f8cad8c3c59a620 100644
--- a/Source/WebKit/WebProcess/WebPage/WebPage.h
+++ b/Source/WebKit/WebProcess/WebPage/WebPage.h
@@ -1138,6 +1138,7 @@ public:
     void connectInspector(const String& targetId, Inspector::FrontendChannel::ConnectionType);
     void disconnectInspector(const String& targetId);
     void sendMessageToTargetBackend(const String& targetId, const String& message);
+    void resumeInspectorIfPausedInNewWindow();
 
     void insertNewlineInQuotedContent();
 
@@ -1387,6 +1388,7 @@ private:
     // Actions
     void tryClose(CompletionHandler<void(bool)>&&);
     void platformDidReceiveLoadParameters(const LoadParameters&);
+    void loadRequestInFrameForInspector(LoadParameters&&, WebCore::FrameIdentifier);
     void loadRequest(LoadParameters&&);
     NO_RETURN void loadRequestWaitingForProcessLaunch(LoadParameters&&, URL&&, WebPageProxyIdentifier, bool);
     void loadData(LoadParameters&&);
@@ -1534,9 +1536,7 @@ private:
     void countStringMatches(const String&, uint32_t findOptions, uint32_t maxMatchCount);
     void replaceMatches(const Vector<uint32_t>& matchIndices, const String& replacementText, bool selectionOnly, CallbackID);
 
-#if USE(COORDINATED_GRAPHICS)
     void sendViewportAttributesChanged(const WebCore::ViewportArguments&);
-#endif
 
     void didChangeSelectedIndexForActivePopupMenu(int32_t newIndex);
     void setTextForActivePopupMenu(int32_t index);
@@ -1997,6 +1997,7 @@ private:
     UserActivity m_userActivity;
 
     uint64_t m_pendingNavigationID { 0 };
+    uint64_t m_pendingFrameNavigationID { 0 };
     Optional<WebsitePoliciesData> m_pendingWebsitePolicies;
 
     bool m_mainFrameProgressCompleted { false };
diff --git a/Source/WebKit/WebProcess/WebPage/WebPage.messages.in b/Source/WebKit/WebProcess/WebPage/WebPage.messages.in
index 1dedf392dd799ac6b7afcd6e2b14447f8ef5c05b..cd5124363f2c596ee5fd01361f32c2f34611cbf7 100644
--- a/Source/WebKit/WebProcess/WebPage/WebPage.messages.in
+++ b/Source/WebKit/WebProcess/WebPage/WebPage.messages.in
@@ -126,6 +126,7 @@ GenerateSyntheticEditingCommand(enum:uint8_t WebKit::SyntheticEditingCommandType
     ConnectInspector(String targetId, Inspector::FrontendChannel::ConnectionType connectionType)
     DisconnectInspector(String targetId)
     SendMessageToTargetBackend(String targetId, String message)
+    ResumeInspectorIfPausedInNewWindow();
 
 #if ENABLE(REMOTE_INSPECTOR)
     SetIndicating(bool indicating);
@@ -168,6 +169,7 @@ GenerateSyntheticEditingCommand(enum:uint8_t WebKit::SyntheticEditingCommandType
     LoadURLInFrame(URL url, String referrer, WebCore::FrameIdentifier frameID)
     LoadDataInFrame(IPC::DataReference data, String MIMEType, String encodingName, URL baseURL, WebCore::FrameIdentifier frameID)
     LoadRequest(struct WebKit::LoadParameters loadParameters)
+    LoadRequestInFrameForInspector(struct WebKit::LoadParameters loadParameters, WebCore::FrameIdentifier frameID)
     LoadRequestWaitingForProcessLaunch(struct WebKit::LoadParameters loadParameters, URL resourceDirectoryURL, WebKit::WebPageProxyIdentifier pageID, bool checkAssumedReadAccessToResourceURL)
     LoadData(struct WebKit::LoadParameters loadParameters)
     LoadAlternateHTML(struct WebKit::LoadParameters loadParameters)
diff --git a/Source/WebKit/WebProcess/WebProcess.cpp b/Source/WebKit/WebProcess/WebProcess.cpp
index 47c9c08adee4585d913346b1abdee867c5f1cb57..1c5802c80f41072ac4bf12f931da5aa89176d14e 100644
--- a/Source/WebKit/WebProcess/WebProcess.cpp
+++ b/Source/WebKit/WebProcess/WebProcess.cpp
@@ -79,6 +79,7 @@
 #include "WebsiteData.h"
 #include "WebsiteDataStoreParameters.h"
 #include "WebsiteDataType.h"
+#include <JavaScriptCore/IdentifiersFactory.h>
 #include <JavaScriptCore/JSLock.h>
 #include <JavaScriptCore/MemoryStatistics.h>
 #include <JavaScriptCore/WasmFaultSignalHandler.h>
@@ -256,6 +257,8 @@ void WebProcess::initializeProcess(const AuxiliaryProcessInitializationParameter
     
     platformInitializeProcess(parameters);
     updateCPULimit();
+
+    Inspector::IdentifiersFactory::initializeWithProcessID(parameters.processIdentifier->toUInt64());
 }
 
 void WebProcess::initializeConnection(IPC::Connection* connection)
diff --git a/Source/WebKitLegacy/mac/WebView/WebHTMLView.mm b/Source/WebKitLegacy/mac/WebView/WebHTMLView.mm
index 472773e34a9f4b82b570ff1d5d73758d624cfa88..eed87820524670236eb4f5dad709f7c052f4a69e 100644
--- a/Source/WebKitLegacy/mac/WebView/WebHTMLView.mm
+++ b/Source/WebKitLegacy/mac/WebView/WebHTMLView.mm
@@ -4245,7 +4245,7 @@ static BOOL currentScrollIsBlit(NSView *clipView)
     _private->handlingMouseDownEvent = NO;
 }
 
-#if ENABLE(TOUCH_EVENTS)
+#if ENABLE(IOS_TOUCH_EVENTS)
 
 - (void)touch:(WebEvent *)event
 {
diff --git a/Source/WebKitLegacy/mac/WebView/WebView.mm b/Source/WebKitLegacy/mac/WebView/WebView.mm
index 4355f7203a6b3f9ecf4468484ec22da271e17aa9..524ad02a5329e35d19ac6e6d4f3ccffc936c2683 100644
--- a/Source/WebKitLegacy/mac/WebView/WebView.mm
+++ b/Source/WebKitLegacy/mac/WebView/WebView.mm
@@ -4343,7 +4343,7 @@ IGNORE_WARNINGS_END
 }
 #endif // PLATFORM(IOS_FAMILY)
 
-#if ENABLE(TOUCH_EVENTS)
+#if ENABLE(IOS_TOUCH_EVENTS)
 - (NSArray *)_touchEventRegions
 {
     auto* frame = [self _mainCoreFrame];
@@ -4389,7 +4389,7 @@ IGNORE_WARNINGS_END
 
     return eventRegionArray;
 }
-#endif // ENABLE(TOUCH_EVENTS)
+#endif // ENABLE(IOS_TOUCH_EVENTS)
 
 // For backwards compatibility with the WebBackForwardList API, we honor both
 // a per-WebView and a per-preferences setting for whether to use the back/forward cache.
diff --git a/Source/cmake/OptionsGTK.cmake b/Source/cmake/OptionsGTK.cmake
index 89f7648bfd63f0e9e1ee49863296aa78b906ff4e..89e23d9e9e8756a3597ef6becf4c4436e5f7403a 100644
--- a/Source/cmake/OptionsGTK.cmake
+++ b/Source/cmake/OptionsGTK.cmake
@@ -3,6 +3,7 @@ include(VersioningUtils)
 
 SET_PROJECT_VERSION(2 27 4)
 set(WEBKITGTK_API_VERSION 4.0)
+set(ENABLE_WEBKIT_LEGACY OFF)
 
 CALCULATE_LIBRARY_VERSIONS_FROM_LIBTOOL_TRIPLE(WEBKIT 80 0 43)
 CALCULATE_LIBRARY_VERSIONS_FROM_LIBTOOL_TRIPLE(JAVASCRIPTCORE 34 0 16)
@@ -172,6 +173,13 @@ WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_CSS_TYPED_OM PRIVATE ${ENABLE_EXPERIMENT
 WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_POINTER_EVENTS PRIVATE ${ENABLE_EXPERIMENTAL_FEATURES})
 WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_CSS_CONIC_GRADIENTS PRIVATE ON)
 
+# Playwright
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_APPLICATION_MANIFEST PRIVATE ON)
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_CSS_TRAILING_WORD PRIVATE ON)
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_CURSOR_VISIBILITY PRIVATE ON)
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_DOWNLOAD_ATTRIBUTE PRIVATE ON)
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_LEGACY_CSS_VENDOR_PREFIXES PRIVATE ON)
+
 include(GStreamerDependencies)
 
 # Finalize the value for all options. Do not attempt to use an option before
diff --git a/Source/cmake/OptionsWPE.cmake b/Source/cmake/OptionsWPE.cmake
index a59f2390c13cb1361fc0d3a537e375277e05d669..c812368e1244235b3a1c5508667a6850bf6c8469 100644
--- a/Source/cmake/OptionsWPE.cmake
+++ b/Source/cmake/OptionsWPE.cmake
@@ -3,6 +3,7 @@ include(VersioningUtils)
 
 SET_PROJECT_VERSION(2 27 4)
 set(WPE_API_VERSION 1.0)
+set(ENABLE_WEBKIT_LEGACY OFF)
 
 CALCULATE_LIBRARY_VERSIONS_FROM_LIBTOOL_TRIPLE(WEBKIT 12 0 9)
 
@@ -66,6 +67,14 @@ WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_CSS_TYPED_OM PRIVATE ${ENABLE_EXPERIMENT
 WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_POINTER_EVENTS PRIVATE ${ENABLE_EXPERIMENTAL_FEATURES})
 WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_CSS_CONIC_GRADIENTS PRIVATE ON)
 
+# Playwright
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_APPLICATION_MANIFEST PRIVATE ON)
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_CSS_TRAILING_WORD PRIVATE ON)
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_CURSOR_VISIBILITY PRIVATE ON)
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_DARK_MODE_CSS PRIVATE ON)
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_DOWNLOAD_ATTRIBUTE PRIVATE ON)
+WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_LEGACY_CSS_VENDOR_PREFIXES PRIVATE ON)
+
 # Public options specific to the WPE port. Do not add any options here unless
 # there is a strong reason we should support changing the value of the option,
 # and the option is not relevant to any other WebKit ports.
diff --git a/Source/cmake/OptionsWin.cmake b/Source/cmake/OptionsWin.cmake
index bca9670392b3d84895b4afc42575b4a1aeccba55..0c0faa7f0e8817261a09ec2536af5e52fa9f06d3 100644
--- a/Source/cmake/OptionsWin.cmake
+++ b/Source/cmake/OptionsWin.cmake
@@ -7,8 +7,9 @@ add_definitions(-D_WINDOWS -DWINVER=0x601 -D_WIN32_WINNT=0x601)
 add_definitions(-DNOMINMAX)
 add_definitions(-DUNICODE -D_UNICODE)
 
+set(ENABLE_WEBKIT_LEGACY OFF)
+
 if ((NOT DEFINED ENABLE_WEBKIT_LEGACY) OR ENABLE_WEBKIT_LEGACY)
-    set(ENABLE_WEBKIT_LEGACY ON)
     set(ENABLE_WEBKIT OFF)
 endif ()
 
@@ -93,6 +94,14 @@ if (${WTF_PLATFORM_WIN_CAIRO})
     WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_WEBDRIVER PRIVATE ${ENABLE_EXPERIMENTAL_FEATURES})
     WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_WEB_CRYPTO PRIVATE ${ENABLE_EXPERIMENTAL_FEATURES})
 
+    # Playwright
+    WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_CSS_CONIC_GRADIENTS PRIVATE ON)
+    WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_CSS_TRAILING_WORD PRIVATE ON)
+    WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_DARK_MODE_CSS PRIVATE ON)
+    WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_DOWNLOAD_ATTRIBUTE PRIVATE ON)
+    WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_POINTER_EVENTS PRIVATE ON)
+    WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_TOUCH_EVENTS PRIVATE ON)
+
     # FIXME: Implement plugin process on Modern WebKit. https://bugs.webkit.org/show_bug.cgi?id=185313
     WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_NETSCAPE_PLUGIN_API PRIVATE OFF)
 else ()
diff --git a/Tools/MiniBrowser/gtk/BrowserTab.c b/Tools/MiniBrowser/gtk/BrowserTab.c
index 9e9978efd3d821c7afcd7b65e14c64e36b355802..a5eef119bddd011470319ac80a0ac443ff0e5441 100644
--- a/Tools/MiniBrowser/gtk/BrowserTab.c
+++ b/Tools/MiniBrowser/gtk/BrowserTab.c
@@ -147,6 +147,11 @@ static void loadChanged(WebKitWebView *webView, WebKitLoadEvent loadEvent, Brows
     gtk_container_foreach(GTK_CONTAINER(tab), (GtkCallback)removeChildIfInfoBar, tab);
 }
 
+static gboolean loadFailed()
+{
+    return TRUE;
+}
+
 static GtkWidget *createInfoBarQuestionMessage(const char *title, const char *text)
 {
     GtkWidget *dialog = gtk_info_bar_new_with_buttons("No", GTK_RESPONSE_NO, "Yes", GTK_RESPONSE_YES, NULL);
@@ -457,6 +462,7 @@ static void browserTabConstructed(GObject *gObject)
     g_signal_connect(tab->webView, "notify::is-loading", G_CALLBACK(isLoadingChanged), tab);
     g_signal_connect(tab->webView, "decide-policy", G_CALLBACK(decidePolicy), tab);
     g_signal_connect(tab->webView, "load-changed", G_CALLBACK(loadChanged), tab);
+    g_signal_connect(tab->webView, "load-failed", G_CALLBACK(loadFailed), tab);
     g_signal_connect(tab->webView, "load-failed-with-tls-errors", G_CALLBACK(loadFailedWithTLSerrors), tab);
     g_signal_connect(tab->webView, "permission-request", G_CALLBACK(decidePermissionRequest), tab);
     g_signal_connect(tab->webView, "run-color-chooser", G_CALLBACK(runColorChooserCallback), tab);
diff --git a/Tools/MiniBrowser/gtk/BrowserWindow.c b/Tools/MiniBrowser/gtk/BrowserWindow.c
index 37f9eefbafd14b69c2bedf928ef379670cfef531..5e7e5db253cf788a079e4a0922833b0778b4640d 100644
--- a/Tools/MiniBrowser/gtk/BrowserWindow.c
+++ b/Tools/MiniBrowser/gtk/BrowserWindow.c
@@ -79,6 +79,8 @@ static const gdouble defaultZoomLevel = 1;
 static const gdouble zoomStep = 1.2;
 static GList *windowList;
 
+static gboolean no_quit = false;
+
 G_DEFINE_TYPE(BrowserWindow, browser_window, GTK_TYPE_WINDOW)
 
 static char *getExternalURI(const char *uri)
@@ -707,7 +709,7 @@ static void browserWindowFinalize(GObject *gObject)
 
     G_OBJECT_CLASS(browser_window_parent_class)->finalize(gObject);
 
-    if (!windowList)
+    if (!windowList && !no_quit)
         gtk_main_quit();
 }
 
@@ -1233,6 +1235,11 @@ void browser_window_set_background_color(BrowserWindow *window, GdkRGBA *rgba)
     gtk_widget_set_app_paintable(GTK_WIDGET(window), TRUE);
 }
 
+void browser_window_no_quit(void)
+{
+    no_quit = true;
+}
+
 static BrowserWindow *findActiveWindow(void)
 {
     GList *l;
diff --git a/Tools/MiniBrowser/gtk/BrowserWindow.h b/Tools/MiniBrowser/gtk/BrowserWindow.h
index 1570d65effb5d601ee3c44a2a7461436f4691c2c..65e62adad0c3684e5cec2f6bc8e7f5281e1f77eb 100644
--- a/Tools/MiniBrowser/gtk/BrowserWindow.h
+++ b/Tools/MiniBrowser/gtk/BrowserWindow.h
@@ -37,7 +37,7 @@ G_BEGIN_DECLS
 #define BROWSER_IS_WINDOW(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), BROWSER_TYPE_WINDOW))
 #define BROWSER_IS_WINDOW_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),  BROWSER_TYPE_WINDOW))
 #define BROWSER_WINDOW_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj),  BROWSER_TYPE_WINDOW, BrowserWindowClass))
-#define BROWSER_DEFAULT_URL            "http://www.webkitgtk.org/"
+#define BROWSER_DEFAULT_URL            "about:blank"
 #define BROWSER_ABOUT_SCHEME           "minibrowser-about"
 
 typedef struct _BrowserWindow        BrowserWindow;
@@ -53,7 +53,7 @@ void browser_window_load_session(BrowserWindow *, const char *sessionFile);
 void browser_window_set_background_color(BrowserWindow*, GdkRGBA*);
 WebKitWebView* browser_window_get_or_create_web_view_for_automation(void);
 WebKitWebView *browser_window_create_web_view_in_new_tab_for_automation(void);
-
+void browser_window_no_quit(void);
 G_END_DECLS
 
 #endif
diff --git a/Tools/MiniBrowser/gtk/main.c b/Tools/MiniBrowser/gtk/main.c
index 4c5147dcd38a53e2feaeaae0fce38f92dc60eba6..77d031add801b2f45c9d90e74afab8802aa08e20 100644
--- a/Tools/MiniBrowser/gtk/main.c
+++ b/Tools/MiniBrowser/gtk/main.c
@@ -53,6 +53,10 @@ static const char *cookiesFile;
 static const char *cookiesPolicy;
 static const char *proxy;
 static gboolean darkMode;
+static gboolean inspectorPipe;
+static gboolean headless;
+static gboolean noStartupWindow;
+static const char *userDataDir;
 static gboolean printVersion;
 
 typedef enum {
@@ -121,6 +125,10 @@ static const GOptionEntry commandLineOptions[] =
     { "ignore-tls-errors", 0, 0, G_OPTION_ARG_NONE, &ignoreTLSErrors, "Ignore TLS errors", NULL },
     { "content-filter", 0, 0, G_OPTION_ARG_FILENAME, &contentFilter, "JSON with content filtering rules", "FILE" },
     { "version", 'v', 0, G_OPTION_ARG_NONE, &printVersion, "Print the WebKitGTK version", NULL },
+    { "inspector-pipe", 0, 0, G_OPTION_ARG_NONE, &inspectorPipe, "Open pipe connection to the remote inspector", NULL },
+    { "user-data-dir", 0, 0, G_OPTION_ARG_STRING, &userDataDir, "Default profile persistence folder location", NULL },
+    { "headless", 0, 0, G_OPTION_ARG_NONE, &headless, "Noop headless operation", NULL },
+    { "no-startup-window", 0, 0, G_OPTION_ARG_NONE, &noStartupWindow, "Do not open default page", NULL },
     { G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &uriArguments, 0, "[URL…]" },
     { 0, 0, 0, 0, 0, 0, 0 }
 };
@@ -498,6 +506,34 @@ static void filterSavedCallback(WebKitUserContentFilterStore *store, GAsyncResul
     g_main_loop_quit(data->mainLoop);
 }
 
+static WebKitWebContext *persistentWebContext = NULL;
+
+static WebKitWebView *createNewPage(WebKitBrowserInspector *browser_inspector, WebKitWebContext *context)
+{
+    if (context == NULL)
+        context = persistentWebContext;
+
+    WebKitWebView *newWebView = WEBKIT_WEB_VIEW(g_object_new(WEBKIT_TYPE_WEB_VIEW,
+        "web-context", context,
+        "is-ephemeral", webkit_web_context_is_ephemeral(context),
+        "is-controlled-by-automation", TRUE,
+        NULL));
+    GtkWidget *newWindow = browser_window_new(NULL, context);
+    browser_window_append_view(BROWSER_WINDOW(newWindow), newWebView);
+    gtk_widget_grab_focus(GTK_WIDGET(newWebView));
+    gtk_widget_show(GTK_WIDGET(newWindow));
+    webkit_web_view_load_uri(newWebView, "about:blank");
+    return newWebView;
+}
+
+static void configureBrowserInspectorPipe()
+{
+    WebKitBrowserInspector* browserInspector = webkit_browser_inspector_get_default();
+    g_signal_connect(browserInspector, "create-new-page", G_CALLBACK(createNewPage), NULL);
+
+    webkit_browser_inspector_initialize_pipe(NULL);
+}
+
 int main(int argc, char *argv[])
 {
 #if ENABLE_DEVELOPER_MODE
@@ -541,8 +577,28 @@ int main(int argc, char *argv[])
         return 0;
     }
 
-    WebKitWebsiteDataManager *manager = (privateMode || automationMode) ? webkit_website_data_manager_new_ephemeral() : webkit_website_data_manager_new(NULL);
+    if (inspectorPipe)
+        configureBrowserInspectorPipe();
+
+    if (noStartupWindow) {
+        browser_window_no_quit();
+        gtk_main();
+        g_clear_object(&webkitSettings);
+        return 0;
+    }
+
+    WebKitWebsiteDataManager *manager;
+    if (userDataDir) {
+        manager = webkit_website_data_manager_new("base-data-directory", userDataDir, "base-cache-directory", userDataDir, NULL);
+        cookiesFile = g_build_filename(userDataDir, "cookies.txt", NULL);
+    } else if (inspectorPipe || privateMode || automationMode) {
+        manager = webkit_website_data_manager_new_ephemeral();
+    } else {
+        manager = webkit_website_data_manager_new(NULL);
+    }
+
     WebKitWebContext *webContext = g_object_new(WEBKIT_TYPE_WEB_CONTEXT, "website-data-manager", manager, "process-swap-on-cross-site-navigation-enabled", TRUE, NULL);
+    persistentWebContext = webContext;
     g_object_unref(manager);
 
     if (cookiesPolicy) {
@@ -648,8 +704,7 @@ int main(int argc, char *argv[])
 
     gtk_main();
 
-    if (privateMode)
-        g_object_unref(webContext);
+    g_object_unref(webContext);
 
     return 0;
 }
diff --git a/Tools/MiniBrowser/win/Common.cpp b/Tools/MiniBrowser/win/Common.cpp
index 87fde928c12a91f13a4f8bc2f2dc24097e42f2d0..40f62e51f18279a1c48d01386120b49a0f9f6029 100644
--- a/Tools/MiniBrowser/win/Common.cpp
+++ b/Tools/MiniBrowser/win/Common.cpp
@@ -278,6 +278,14 @@ CommandLineOptions parseCommandLine()
 #if ENABLE(WEBKIT)
         else if (!wcsicmp(argv[i], L"--wk2") || !wcsicmp(argv[i], L"--webkit"))
             options.windowType = BrowserWindowType::WebKit;
+        else if (!wcsicmp(argv[i], L"--inspector-pipe"))
+            options.inspectorPipe = true;
+        else if (!wcsncmp(argv[i], L"--user-data-dir=", 16))
+            options.userDataDir = argv[i] + 16;
+        else if (!wcsicmp(argv[i], L"--headless"))
+            options.headless = true;
+        else if (!wcsicmp(argv[i], L"--no-startup-window"))
+            options.noStartupWindow = true;
 #endif
         else if (!options.requestedURL)
             options.requestedURL = argv[i];
diff --git a/Tools/MiniBrowser/win/Common.h b/Tools/MiniBrowser/win/Common.h
index d996feb64e02d7399f2ed0b34d3d0dd03133f824..044069ecd792654e533bac276b98ad45410fb9c7 100644
--- a/Tools/MiniBrowser/win/Common.h
+++ b/Tools/MiniBrowser/win/Common.h
@@ -36,8 +36,12 @@ enum class BrowserWindowType {
 struct CommandLineOptions {
     bool usesLayeredWebView { };
     bool useFullDesktop { };
+    bool inspectorPipe { };
+    bool headless { };
+    bool noStartupWindow { };
     BrowserWindowType windowType;
     _bstr_t requestedURL;
+    _bstr_t userDataDir;
 
     CommandLineOptions()
 #if ENABLE(WEBKIT)
diff --git a/Tools/MiniBrowser/win/MainWindow.cpp b/Tools/MiniBrowser/win/MainWindow.cpp
index 08131e61107bc4163c4fb1e9a65ee5a1ecda6b04..d157cb5c13bf61ad2593989353237629ae60d710 100644
--- a/Tools/MiniBrowser/win/MainWindow.cpp
+++ b/Tools/MiniBrowser/win/MainWindow.cpp
@@ -60,6 +60,14 @@ static INT_PTR CALLBACK About(HWND, UINT, WPARAM, LPARAM);
 std::wstring MainWindow::s_windowClass;
 size_t MainWindow::s_numInstances;
 
+bool MainWindow::s_headless = false;
+bool MainWindow::s_noStartupWindow = false;
+
+void MainWindow::configure(bool headless, bool noStartupWindow) {
+    s_headless = headless;
+    s_noStartupWindow = noStartupWindow;
+}
+
 static std::wstring loadString(int id)
 {
     constexpr size_t length = 100;
@@ -102,7 +110,9 @@ bool MainWindow::isInstance(HWND hwnd)
     return s_windowClass == buff;
 }
 
-MainWindow::MainWindow()
+MainWindow::MainWindow(WKContextRef context, WKWebsiteDataStoreRef dataStore)
+    : m_context(context)
+    , m_dataStore(dataStore)
 {
     s_numInstances++;
 }
@@ -112,9 +122,9 @@ MainWindow::~MainWindow()
     s_numInstances--;
 }
 
-Ref<MainWindow> MainWindow::create()
+Ref<MainWindow> MainWindow::create(WKContextRef context, WKWebsiteDataStoreRef dataStore)
 {
-    return adoptRef(*new MainWindow());
+    return adoptRef(*new MainWindow(context, dataStore));
 }
 
 void MainWindow::createToolbar(HINSTANCE hInstance)
@@ -202,24 +212,26 @@ bool MainWindow::init(BrowserWindowFactory factory, HINSTANCE hInstance, bool us
 
     auto title = loadString(IDS_APP_TITLE);
 
-    m_hMainWnd = CreateWindow(s_windowClass.c_str(), title.c_str(), WS_OVERLAPPEDWINDOW,
-        CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, 0, 0, hInstance, this);
+    m_hMainWnd = CreateWindowExW(s_headless ? WS_EX_NOACTIVATE : 0, s_windowClass.c_str(), title.c_str(),
+        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, 0, 0, hInstance, this);
 
     if (!m_hMainWnd)
         return false;
 
+    if (!s_headless) {
 #if !ENABLE(WEBKIT)
-    EnableMenuItem(GetMenu(m_hMainWnd), IDM_NEW_WEBKIT_WINDOW, MF_GRAYED);
+        EnableMenuItem(GetMenu(m_hMainWnd), IDM_NEW_WEBKIT_WINDOW, MF_GRAYED);
 #endif
 #if !ENABLE(WEBKIT_LEGACY)
-    EnableMenuItem(GetMenu(m_hMainWnd), IDM_NEW_WEBKITLEGACY_WINDOW, MF_GRAYED);
+        EnableMenuItem(GetMenu(m_hMainWnd), IDM_NEW_WEBKITLEGACY_WINDOW, MF_GRAYED);
 #endif
 
-    createToolbar(hInstance);
-    if (!m_hToolbarWnd)
-        return false;
+      createToolbar(hInstance);
+      if (!m_hToolbarWnd)
+          return false;
+    }
 
-    m_browserWindow = factory(*this, m_hMainWnd, usesLayeredWebView);
+    m_browserWindow = factory(*this, m_hMainWnd, m_context.get(), m_dataStore.get(), usesLayeredWebView);
     if (!m_browserWindow)
         return false;
     HRESULT hr = m_browserWindow->init();
@@ -228,7 +240,13 @@ bool MainWindow::init(BrowserWindowFactory factory, HINSTANCE hInstance, bool us
 
     updateDeviceScaleFactor();
     resizeSubViews();
-    SetFocus(m_hURLBarWnd);
+
+    if (s_headless) {
+        SetMenu(m_hMainWnd, NULL);
+    } else {
+        SetFocus(m_hURLBarWnd);
+        ShowWindow(m_hMainWnd, SW_SHOW);
+    }
     return true;
 }
 
@@ -236,6 +254,10 @@ void MainWindow::resizeSubViews()
 {
     RECT rcClient;
     GetClientRect(m_hMainWnd, &rcClient);
+    if (s_headless) {
+        MoveWindow(m_browserWindow->hwnd(), 0, 0, rcClient.right, rcClient.bottom, true);
+        return;
+    }
 
     resizeToolbar(rcClient.right);
 
@@ -254,6 +276,9 @@ LRESULT CALLBACK MainWindow::WndProc(HWND hWnd, UINT message, WPARAM wParam, LPA
 {
     LRESULT result = 0;
     RefPtr<MainWindow> thisWindow = reinterpret_cast<MainWindow*>(GetWindowLongPtr(hWnd, GWLP_USERDATA));
+    if (!thisWindow && message != WM_CREATE)
+        return DefWindowProc(hWnd, message, wParam, lParam);
+
     switch (message) {
     case WM_ACTIVATE:
         switch (LOWORD(wParam)) {
@@ -309,17 +334,15 @@ LRESULT CALLBACK MainWindow::WndProc(HWND hWnd, UINT message, WPARAM wParam, LPA
             break;
 #if ENABLE(WEBKIT)
         case IDM_NEW_WEBKIT_WINDOW: {
-            auto& newWindow = MainWindow::create().leakRef();
+            auto& newWindow = MainWindow::create(thisWindow->m_context.get(), thisWindow->m_dataStore.get()).leakRef();
             newWindow.init(WebKitBrowserWindow::create, hInst);
-            ShowWindow(newWindow.hwnd(), SW_SHOW);
             break;
         }
 #endif
 #if ENABLE(WEBKIT_LEGACY)
         case IDM_NEW_WEBKITLEGACY_WINDOW: {
-            auto& newWindow = MainWindow::create().leakRef();
+            auto& newWindow = MainWindow::create(thisWindow->m_context.get(), thisWindow->m_dataStore.get()).leakRef();
             newWindow.init(WebKitLegacyBrowserWindow::create, hInst);
-            ShowWindow(newWindow.hwnd(), SW_SHOW);
             break;
         }
 #endif
@@ -384,7 +407,7 @@ LRESULT CALLBACK MainWindow::WndProc(HWND hWnd, UINT message, WPARAM wParam, LPA
     case WM_DESTROY:
         SetWindowLongPtr(hWnd, GWLP_USERDATA, 0);
         thisWindow->deref();
-        if (s_numInstances > 1)
+        if (s_noStartupWindow || s_numInstances > 1)
             return 0;
 #if USE(CF)
         CFRunLoopStop(CFRunLoopGetMain());
@@ -443,6 +466,9 @@ void MainWindow::setDefaultURLToCurrentURL()
 
 bool MainWindow::toggleMenuItem(UINT menuID)
 {
+    if (s_headless)
+        return (INT_PTR)FALSE;
+
     HMENU menu = ::GetMenu(hwnd());
 
     switch (menuID) {
@@ -518,6 +544,8 @@ INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
 
 INT_PTR CALLBACK MainWindow::cachesDialogProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
 {
+    if (s_headless)
+        return (INT_PTR)FALSE;
     MainWindow& thisWindow = *reinterpret_cast<MainWindow*>(GetWindowLongPtr(hDlg, DWLP_USER));
     switch (message) {
     case WM_INITDIALOG:
@@ -548,6 +576,8 @@ INT_PTR CALLBACK MainWindow::cachesDialogProc(HWND hDlg, UINT message, WPARAM wP
 
 INT_PTR CALLBACK MainWindow::customUserAgentDialogProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
 {
+    if (s_headless)
+        return (INT_PTR)FALSE;
     MainWindow& thisWindow = *reinterpret_cast<MainWindow*>(GetWindowLongPtr(hDlg, DWLP_USER));
     switch (message) {
     case WM_INITDIALOG: {
@@ -594,27 +624,26 @@ void MainWindow::loadURL(std::wstring url)
         if (SUCCEEDED(::UrlCreateFromPath(url.c_str(), fileURL, &fileURLLength, 0)))
             url = fileURL;
     }
-    if (url.find(L"://") == url.npos)
+    if (url.find(L"://") == url.npos && url.find(L"about:blank") == url.npos)
         url = L"http://" + url;
 
     if (FAILED(m_browserWindow->loadURL(_bstr_t(url.c_str()))))
         return;
 
-    SetFocus(m_browserWindow->hwnd());
+    if (!s_headless)
+        SetFocus(m_browserWindow->hwnd());
 }
 
 void MainWindow::goHome()
 {
-    std::wstring defaultURL = L"https://www.webkit.org/";
-    wchar_t url[INTERNET_MAX_URL_LENGTH];
-    DWORD urlLength = sizeof(url);
-    if (!RegGetValue(HKEY_CURRENT_USER, kMiniBrowserRegistryKey, L"DefaultURL", RRF_RT_REG_SZ, nullptr, &url, &urlLength))
-        defaultURL = url;
+    std::wstring defaultURL = L"about:blank";
     loadURL(defaultURL);
 }
 
 void MainWindow::onURLBarEnter()
 {
+    if (s_headless)
+        return;
     wchar_t url[INTERNET_MAX_URL_LENGTH];
     GetWindowText(m_hURLBarWnd, url, INTERNET_MAX_URL_LENGTH);
     loadURL(url);
@@ -622,6 +651,8 @@ void MainWindow::onURLBarEnter()
 
 void MainWindow::updateDeviceScaleFactor()
 {
+    if (s_headless)
+        return;
     if (m_hURLBarFont)
         ::DeleteObject(m_hURLBarFont);
 
@@ -638,6 +669,8 @@ void MainWindow::updateDeviceScaleFactor()
 
 void MainWindow::progressChanged(double progress)
 {
+    if (s_headless)
+        return;
     std::wostringstream text;
     text << static_cast<int>(progress * 100) << L'%';
     SetWindowText(m_hProgressIndicator, text.str().c_str());
@@ -645,10 +678,14 @@ void MainWindow::progressChanged(double progress)
 
 void MainWindow::progressFinished()
 {
+    if (s_headless)
+        return;
     SetWindowText(m_hProgressIndicator, L"");
 }
 
 void MainWindow::activeURLChanged(std::wstring url)
 {
+    if (s_headless)
+        return;
     SetWindowText(m_hURLBarWnd, url.c_str());
 }
diff --git a/Tools/MiniBrowser/win/MainWindow.h b/Tools/MiniBrowser/win/MainWindow.h
index d79c6fdc4fa05e1e4b9acdcc6932e571163320eb..99718b19797788634f4233a8892729b57ae642d0 100644
--- a/Tools/MiniBrowser/win/MainWindow.h
+++ b/Tools/MiniBrowser/win/MainWindow.h
@@ -26,6 +26,8 @@
 #pragma once
 
 #include "BrowserWindow.h"
+#include <WebKit/WKBase.h>
+#include <WebKit/WKRetainPtr.h>
 #include <functional>
 #include <memory>
 #include <string>
@@ -33,9 +35,10 @@
 
 class MainWindow final : public RefCounted<MainWindow>, public BrowserWindowClient {
 public:
-    using BrowserWindowFactory = std::function<Ref<BrowserWindow>(BrowserWindowClient&, HWND mainWnd, bool usesLayeredWebView)>;
+    using BrowserWindowFactory = std::function<Ref<BrowserWindow>(BrowserWindowClient&, HWND mainWnd, WKContextRef, WKWebsiteDataStoreRef, bool usesLayeredWebView)>;
+    static void configure(bool headless, bool noStartupWindow);
 
-    static Ref<MainWindow> create();
+    static Ref<MainWindow> create(WKContextRef context, WKWebsiteDataStoreRef dataStore);
 
     ~MainWindow();
     bool init(BrowserWindowFactory, HINSTANCE hInstance, bool usesLayeredWebView = false);
@@ -56,8 +59,10 @@ private:
     static void registerClass(HINSTANCE hInstance);
     static std::wstring s_windowClass;
     static size_t s_numInstances;
+    static bool s_headless;
+    static bool s_noStartupWindow;
 
-    MainWindow();
+    MainWindow(WKContextRef context, WKWebsiteDataStoreRef dataStore);
     void setDefaultURLToCurrentURL();
     bool toggleMenuItem(UINT menuID);
     void onURLBarEnter();
@@ -78,6 +83,8 @@ private:
     HWND m_hProgressIndicator { nullptr };
     HWND m_hCacheWnd { nullptr };
     HGDIOBJ m_hURLBarFont { nullptr };
+    WKRetainPtr<WKContextRef> m_context; 
+    WKRetainPtr<WKWebsiteDataStoreRef> m_dataStore;
     RefPtr<BrowserWindow> m_browserWindow;
     int m_toolbarItemsWidth { };
 };
diff --git a/Tools/MiniBrowser/win/WebKitBrowserWindow.cpp b/Tools/MiniBrowser/win/WebKitBrowserWindow.cpp
index dc2b3f257600e3f4d172875ebb821769a160979d..9e0072a181ebea8834b96ba5c0020a722f7f3cd4 100644
--- a/Tools/MiniBrowser/win/WebKitBrowserWindow.cpp
+++ b/Tools/MiniBrowser/win/WebKitBrowserWindow.cpp
@@ -107,7 +107,7 @@ WKRetainPtr<WKURLRef> createWKURL(const std::wstring& str)
     return adoptWK(WKURLCreateWithUTF8CString(utf8.data()));
 }
 
-Ref<BrowserWindow> WebKitBrowserWindow::create(BrowserWindowClient& client, HWND mainWnd, bool)
+Ref<BrowserWindow> WebKitBrowserWindow::create(BrowserWindowClient& client, HWND mainWnd, WKContextRef context, WKWebsiteDataStoreRef dataStore, bool)
 {
     auto conf = adoptWK(WKPageConfigurationCreate());
 
@@ -121,8 +121,8 @@ Ref<BrowserWindow> WebKitBrowserWindow::create(BrowserWindowClient& client, HWND
     WKPreferencesSetDeveloperExtrasEnabled(prefs.get(), true);
     WKPageConfigurationSetPreferences(conf.get(), prefs.get());
 
-    auto context =adoptWK(WKContextCreateWithConfiguration(nullptr));
-    WKPageConfigurationSetContext(conf.get(), context.get());
+    WKPageConfigurationSetContext(conf.get(), context);
+    WKPageConfigurationSetWebsiteDataStore(conf.get(), dataStore);
 
     return adoptRef(*new WebKitBrowserWindow(client, conf.get(), mainWnd));
 }
@@ -143,11 +143,17 @@ WebKitBrowserWindow::WebKitBrowserWindow(BrowserWindowClient& client, WKPageConf
     navigationClient.didReceiveAuthenticationChallenge = didReceiveAuthenticationChallenge;
     WKPageSetPageNavigationClient(page, &navigationClient.base);
 
-    WKPageUIClientV13 uiClient = { };
-    uiClient.base.version = 13;
+    WKPageUIClientV14 uiClient = { };
+    uiClient.base.version = 14;
     uiClient.base.clientInfo = this;
     uiClient.createNewPage = createNewPage;
     uiClient.didNotHandleKeyEvent = didNotHandleKeyEvent;
+    uiClient.close = closeWindow;
+    uiClient.runJavaScriptAlert = runJavaScriptAlert;
+    uiClient.runJavaScriptConfirm = runJavaScriptConfirm;
+    uiClient.runJavaScriptPrompt = runJavaScriptPrompt;
+    uiClient.runBeforeUnloadConfirmPanel = runBeforeUnloadConfirmPanel;
+    uiClient.handleJavaScriptDialog = handleJavaScriptDialog;
     WKPageSetPageUIClient(page, &uiClient.base);
 
     WKPageStateClientV0 stateClient = { };
@@ -159,7 +165,6 @@ WebKitBrowserWindow::WebKitBrowserWindow(BrowserWindowClient& client, WKPageConf
     stateClient.didChangeActiveURL = didChangeActiveURL;
     WKPageSetPageStateClient(page, &stateClient.base);
 
-    updateProxySettings();
     resetZoom();
 }
 
@@ -183,6 +188,29 @@ void WebKitBrowserWindow::updateProxySettings()
     WKWebsiteDataStoreEnableCustomNetworkProxySettings(store, url.get(), excludeHosts.get());
 }
 
+WebKitBrowserWindow::~WebKitBrowserWindow()
+{
+    if (m_alertDialog) {
+        WKRelease(m_alertDialog);
+        m_alertDialog = NULL;
+    }
+
+    if (m_confirmDialog) {
+        WKRelease(m_confirmDialog);
+        m_confirmDialog = NULL;
+    }
+
+    if (m_promptDialog) {
+        WKRelease(m_promptDialog);
+        m_promptDialog = NULL;
+    }
+
+    if (m_beforeUnloadDialog) {
+        WKRelease(m_beforeUnloadDialog);
+        m_beforeUnloadDialog = NULL;
+    }
+}
+
 HRESULT WebKitBrowserWindow::init()
 {
     return S_OK;
@@ -251,7 +279,6 @@ void WebKitBrowserWindow::openProxySettings()
 {
     if (askProxySettings(m_hMainWnd, m_proxy))
         updateProxySettings();
-
 }
 
 void WebKitBrowserWindow::setUserAgent(_bstr_t& customUAString)
@@ -381,18 +408,94 @@ bool WebKitBrowserWindow::canTrustServerCertificate(WKProtectionSpaceRef protect
     return false;
 }
 
-WKPageRef WebKitBrowserWindow::createNewPage(WKPageRef page, WKPageConfigurationRef configuration, WKNavigationActionRef navigationAction, WKWindowFeaturesRef windowFeatures, const void *clientInfo)
+void WebKitBrowserWindow::closeWindow(WKPageRef page, const void* clientInfo)
 {
-    auto& newWindow = MainWindow::create().leakRef();
-    auto factory = [configuration](BrowserWindowClient& client, HWND mainWnd, bool) -> auto {
+    auto& thisWindow = toWebKitBrowserWindow(clientInfo);
+    PostMessage(thisWindow.m_hMainWnd, WM_CLOSE, 0, 0);
+}
+
+void WebKitBrowserWindow::runJavaScriptAlert(WKPageRef page, WKStringRef alertText, WKFrameRef frame, WKSecurityOriginRef securityOrigin, WKPageRunJavaScriptAlertResultListenerRef listener, const void *clientInfo)
+{
+    auto& thisWindow = toWebKitBrowserWindow(clientInfo);
+    WKRetain(listener);
+    thisWindow.m_alertDialog = listener;
+}
+
+void WebKitBrowserWindow::runJavaScriptConfirm(WKPageRef page, WKStringRef message, WKFrameRef frame, WKSecurityOriginRef securityOrigin, WKPageRunJavaScriptConfirmResultListenerRef listener, const void *clientInfo)
+{
+    auto& thisWindow = toWebKitBrowserWindow(clientInfo);
+    WKRetain(listener);
+    thisWindow.m_confirmDialog = listener;
+}
+
+void WebKitBrowserWindow::runJavaScriptPrompt(WKPageRef page, WKStringRef message, WKStringRef defaultValue, WKFrameRef frame, WKSecurityOriginRef securityOrigin, WKPageRunJavaScriptPromptResultListenerRef listener, const void *clientInfo)
+{
+    auto& thisWindow = toWebKitBrowserWindow(clientInfo);
+    WKRetain(listener);
+    thisWindow.m_promptDialog = listener;
+}
+
+void WebKitBrowserWindow::runBeforeUnloadConfirmPanel(WKPageRef page, WKStringRef message, WKFrameRef frame, WKPageRunBeforeUnloadConfirmPanelResultListenerRef listener, const void *clientInfo)
+{
+    auto& thisWindow = toWebKitBrowserWindow(clientInfo);
+    WKRetain(listener);
+    thisWindow.m_beforeUnloadDialog = listener;
+}
+    
+void WebKitBrowserWindow::handleJavaScriptDialog(WKPageRef page, bool accept, WKStringRef value, const void *clientInfo)
+{
+    auto& thisWindow = toWebKitBrowserWindow(clientInfo);
+    if (thisWindow.m_alertDialog) {
+        WKPageRunJavaScriptAlertResultListenerCall(thisWindow.m_alertDialog);
+        WKRelease(thisWindow.m_alertDialog);
+        thisWindow.m_alertDialog = NULL;
+    }
+
+    if (thisWindow.m_confirmDialog) {
+        WKPageRunJavaScriptConfirmResultListenerCall(thisWindow.m_confirmDialog, accept);
+        WKRelease(thisWindow.m_confirmDialog);
+        thisWindow.m_confirmDialog = NULL;
+    }
+
+    if (thisWindow.m_promptDialog) {
+        WKPageRunJavaScriptPromptResultListenerCall(thisWindow.m_promptDialog, accept ? value : NULL);
+        WKRelease(thisWindow.m_promptDialog);
+        thisWindow.m_promptDialog = NULL;
+    }
+
+    if (thisWindow.m_beforeUnloadDialog) {
+        WKPageRunBeforeUnloadConfirmPanelResultListenerCall(thisWindow.m_beforeUnloadDialog, accept);
+        WKRelease(thisWindow.m_beforeUnloadDialog);
+        thisWindow.m_beforeUnloadDialog = NULL;
+    }
+}
+
+WKPageRef WebKitBrowserWindow::createPageCallback(WKPageConfigurationRef configuration)
+{
+    return WebKitBrowserWindow::createViewCallback(configuration, true);
+}
+
+WKPageRef WebKitBrowserWindow::createViewCallback(WKPageConfigurationRef configuration, bool navigate)
+{
+    auto context = WKPageConfigurationGetContext(configuration);
+    auto dataStore = WKPageConfigurationGetWebsiteDataStore(configuration);
+    auto& newWindow = MainWindow::create(context, dataStore).leakRef();
+    auto factory = [configuration](BrowserWindowClient& client, HWND mainWnd, WKContextRef, WKWebsiteDataStoreRef, bool) -> auto {
         return adoptRef(*new WebKitBrowserWindow(client, configuration, mainWnd));
     };
     bool ok = newWindow.init(factory, hInst);
-    if (!ok)
-        return nullptr;
-    ShowWindow(newWindow.hwnd(), SW_SHOW);
+    if (navigate)
+        newWindow.browserWindow()->loadURL(_bstr_t("about:blank").GetBSTR());
+
     auto& newBrowserWindow = *static_cast<WebKitBrowserWindow*>(newWindow.browserWindow());
-    WKRetainPtr<WKPageRef> newPage = WKViewGetPage(newBrowserWindow.m_view.get());
+    return WKViewGetPage(newBrowserWindow.m_view.get());
+}
+
+
+WKPageRef WebKitBrowserWindow::createNewPage(WKPageRef, WKPageConfigurationRef configuration, WKNavigationActionRef, WKWindowFeaturesRef, const void*)
+{
+    // Retain popups as per API contract.
+    WKRetainPtr<WKPageRef> newPage = createViewCallback(configuration, false);
     return newPage.leakRef();
 }
 
diff --git a/Tools/MiniBrowser/win/WebKitBrowserWindow.h b/Tools/MiniBrowser/win/WebKitBrowserWindow.h
index 373d0de77e852c673a6615e0acedd5195e3c021b..cfeb4f806f79d1a213fdb13346e2b383b9a64273 100644
--- a/Tools/MiniBrowser/win/WebKitBrowserWindow.h
+++ b/Tools/MiniBrowser/win/WebKitBrowserWindow.h
@@ -26,6 +26,7 @@
 
 #include "BrowserWindow.h"
 #include "Common.h"
+#include <WebKit/WKBase.h>
 #include <WebKit/WKRetainPtr.h>
 #include <WebKit/WebKit2_C.h>
 #include <unordered_map>
@@ -33,10 +34,13 @@
 
 class WebKitBrowserWindow : public BrowserWindow {
 public:
-    static Ref<BrowserWindow> create(BrowserWindowClient&, HWND mainWnd, bool useLayeredWebView = false);
+    static Ref<BrowserWindow> create(BrowserWindowClient&, HWND mainWnd, WKContextRef, WKWebsiteDataStoreRef, bool useLayeredWebView = false);
+    static WKPageRef createPageCallback(WKPageConfigurationRef);
 
 private:
+    static WKPageRef createViewCallback(WKPageConfigurationRef, bool navigate);
     WebKitBrowserWindow(BrowserWindowClient&, WKPageConfigurationRef, HWND mainWnd);
+    ~WebKitBrowserWindow() override;
 
     HRESULT init() override;
     HWND hwnd() override;
@@ -71,6 +75,12 @@ private:
     static void didChangeActiveURL(const void*);
     static void didReceiveAuthenticationChallenge(WKPageRef, WKAuthenticationChallengeRef, const void*);
     static WKPageRef createNewPage(WKPageRef, WKPageConfigurationRef, WKNavigationActionRef, WKWindowFeaturesRef, const void *);
+    static void closeWindow(WKPageRef, const void*);
+    static void runJavaScriptAlert(WKPageRef page, WKStringRef alertText, WKFrameRef frame, WKSecurityOriginRef securityOrigin, WKPageRunJavaScriptAlertResultListenerRef listener, const void *clientInfo);
+    static void runJavaScriptConfirm(WKPageRef page, WKStringRef message, WKFrameRef frame, WKSecurityOriginRef securityOrigin, WKPageRunJavaScriptConfirmResultListenerRef listener, const void *clientInfo);
+    static void runJavaScriptPrompt(WKPageRef page, WKStringRef message, WKStringRef defaultValue, WKFrameRef frame, WKSecurityOriginRef securityOrigin, WKPageRunJavaScriptPromptResultListenerRef listener, const void *clientInfo);
+    static void runBeforeUnloadConfirmPanel(WKPageRef page, WKStringRef message, WKFrameRef frame, WKPageRunBeforeUnloadConfirmPanelResultListenerRef listener, const void *clientInfo);
+    static void handleJavaScriptDialog(WKPageRef page, bool accept, WKStringRef value, const void *clientInfo);
     static void didNotHandleKeyEvent(WKPageRef, WKNativeEventPtr, const void*);
 
     BrowserWindowClient& m_client;
@@ -78,4 +88,8 @@ private:
     HWND m_hMainWnd { nullptr };
     ProxySettings m_proxy { };
     std::unordered_map<std::wstring, std::wstring> m_acceptedServerTrustCerts;
+    WKPageRunJavaScriptAlertResultListenerRef m_alertDialog = { };
+    WKPageRunJavaScriptConfirmResultListenerRef m_confirmDialog = { };
+    WKPageRunJavaScriptPromptResultListenerRef m_promptDialog = { };
+    WKPageRunBeforeUnloadConfirmPanelResultListenerRef m_beforeUnloadDialog = { };
 };
diff --git a/Tools/MiniBrowser/win/WinMain.cpp b/Tools/MiniBrowser/win/WinMain.cpp
index 6008ca19e26a938cf962c0c336299fff7d13f9a3..8005d72f8c0d9ef82efda8aec1ff0e7d96501ae8 100644
--- a/Tools/MiniBrowser/win/WinMain.cpp
+++ b/Tools/MiniBrowser/win/WinMain.cpp
@@ -31,6 +31,10 @@
 #include "stdafx.h"
 #include "Common.h"
 #include "MiniBrowserLibResource.h"
+#include "MiniBrowserReplace.h"
+#include <WebKit/WKContext.h>
+#include <WebKit/WKWebsiteDataStoreConfigurationRef.h>
+#include <WebKit/WKWebsiteDataStoreRef.h>
 #include <wtf/win/SoftLinking.h>
 
 #if USE(CF)
@@ -46,9 +50,25 @@
 #include <WebKitLegacy/WebKitCOMAPI.h>
 #endif
 
+#include <wtf/MainThread.h>
+#include <WebKit/WKInspector.h>
+
 SOFT_LINK_LIBRARY(user32);
 SOFT_LINK_OPTIONAL(user32, SetProcessDpiAwarenessContext, BOOL, STDAPICALLTYPE, (DPI_AWARENESS_CONTEXT));
 
+WKRetainPtr<WKStringRef> toWK(const std::string& string)
+{
+    return adoptWK(WKStringCreateWithUTF8CString(string.c_str()));
+}
+
+std::string toUTF8String(const wchar_t* src, size_t srcLength)
+{
+    int length = WideCharToMultiByte(CP_UTF8, 0, src, srcLength, 0, 0, nullptr, nullptr);
+    std::vector<char> buffer(length);
+    size_t actualLength = WideCharToMultiByte(CP_UTF8, 0, src, srcLength, buffer.data(), length, nullptr, nullptr);
+    return { buffer.data(), actualLength };
+}
+
 int WINAPI wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPWSTR lpstrCmdLine, _In_ int nCmdShow)
 {
 #ifdef _CRTDBG_MAP_ALLOC
@@ -66,6 +86,11 @@ int WINAPI wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance,
     InitCommonControlsEx(&InitCtrlEx);
 
     auto options = parseCommandLine();
+    if (options.inspectorPipe) {
+        WKInspectorInitializeRemoteInspectorPipe(
+            WebKitBrowserWindow::createPageCallback,
+            []() { PostQuitMessage(0); });
+    }
 
     if (options.useFullDesktop)
         computeFullDesktopFrame();
@@ -74,32 +99,50 @@ int WINAPI wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance,
     OleInitialize(nullptr);
 
     if (SetProcessDpiAwarenessContextPtr())
-        SetProcessDpiAwarenessContextPtr()(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
-    else
-        ::SetProcessDPIAware();
+        SetProcessDpiAwarenessContextPtr()(DPI_AWARENESS_CONTEXT_UNAWARE);
+
+    MainWindow::configure(options.headless, options.noStartupWindow);
 
+    if (!options.noStartupWindow) {
 #if !ENABLE(WEBKIT_LEGACY)
-    auto factory = WebKitBrowserWindow::create;
+        auto factory = WebKitBrowserWindow::create;
 #elif !ENABLE(WEBKIT)
-    auto factory = WebKitLegacyBrowserWindow::create;
+        auto factory = WebKitLegacyBrowserWindow::create;
 #else
-    auto factory = options.windowType == BrowserWindowType::WebKit ? WebKitBrowserWindow::create : WebKitLegacyBrowserWindow::create;
+        auto factory = options.windowType == BrowserWindowType::WebKit ? WebKitBrowserWindow::create : WebKitLegacyBrowserWindow::create;
 #endif
-    auto& mainWindow = MainWindow::create().leakRef();
-    HRESULT hr = mainWindow.init(factory, hInst, options.usesLayeredWebView);
-    if (FAILED(hr))
-        goto exit;
 
-    ShowWindow(mainWindow.hwnd(), nCmdShow);
+        auto configuration = adoptWK(WKWebsiteDataStoreConfigurationCreate());
+        if (options.userDataDir.length()) {
+            std::string profileFolder = toUTF8String(options.userDataDir, options.userDataDir.length());
+            WKWebsiteDataStoreConfigurationSetApplicationCacheDirectory(configuration.get(), toWK(profileFolder + "\\ApplicationCache").get());
+            WKWebsiteDataStoreConfigurationSetNetworkCacheDirectory(configuration.get(), toWK(profileFolder + "\\Cache").get());
+            WKWebsiteDataStoreConfigurationSetCacheStorageDirectory(configuration.get(), toWK(profileFolder + "\\CacheStorage").get());
+            WKWebsiteDataStoreConfigurationSetIndexedDBDatabaseDirectory(configuration.get(), toWK(profileFolder + "\\Databases" + "\\IndexedDB").get());
+            WKWebsiteDataStoreConfigurationSetLocalStorageDirectory(configuration.get(), toWK(profileFolder + "\\LocalStorage").get());
+            WKWebsiteDataStoreConfigurationSetWebSQLDatabaseDirectory(configuration.get(), toWK(profileFolder + "\\Databases" + "\\WebSQL").get());
+            WKWebsiteDataStoreConfigurationSetMediaKeysStorageDirectory(configuration.get(), toWK(profileFolder + "\\MediaKeys").get());
+            WKWebsiteDataStoreConfigurationSetResourceLoadStatisticsDirectory(configuration.get(), toWK(profileFolder + "\\ResourceLoadStatistics").get());
+            WKWebsiteDataStoreConfigurationSetServiceWorkerRegistrationDirectory(configuration.get(), toWK(profileFolder + "\\ServiceWorkers").get());
+        }
+        auto context = adoptWK(WKContextCreateWithConfiguration(nullptr));
+        auto dataStore = adoptWK(WKWebsiteDataStoreCreateWithConfiguration(configuration.get()));
+        WKContextSetPrimaryDataStore(context.get(), dataStore.get());
+
+        auto& mainWindow = MainWindow::create(context.get(), dataStore.get()).leakRef();
+        HRESULT hr = mainWindow.init(factory, hInst, options.usesLayeredWebView);
+        if (FAILED(hr))
+            goto exit;
+
+        if (options.requestedURL.length())
+            mainWindow.loadURL(options.requestedURL.GetBSTR());
+        else
+            mainWindow.goHome();
+    }
 
     hAccelTable = LoadAccelerators(hInst, MAKEINTRESOURCE(IDC_MINIBROWSER));
     hPreAccelTable = LoadAccelerators(hInst, MAKEINTRESOURCE(IDR_ACCELERATORS_PRE));
 
-    if (options.requestedURL.length())
-        mainWindow.loadURL(options.requestedURL.GetBSTR());
-    else
-        mainWindow.goHome();
-
 #pragma warning(disable:4509)
 
     // Main message loop:
diff --git a/Tools/MiniBrowser/wpe/CMakeLists.txt b/Tools/MiniBrowser/wpe/CMakeLists.txt
index 04d3630dc2b0f5e937af173046268001da003753..ba0a60b832cd353776bb50b8198df2d8c4ee9f68 100644
--- a/Tools/MiniBrowser/wpe/CMakeLists.txt
+++ b/Tools/MiniBrowser/wpe/CMakeLists.txt
@@ -13,6 +13,7 @@ set(MiniBrowser_INCLUDE_DIRECTORIES
 
 set(MiniBrowser_SYSTEM_INCLUDE_DIRECTORIES
     ${ATK_INCLUDE_DIRS}
+    ${GLIB_INCLUDE_DIRS}
     ${WPEBACKEND_FDO_INCLUDE_DIRS}
 )
 
diff --git a/Tools/MiniBrowser/wpe/main.cpp b/Tools/MiniBrowser/wpe/main.cpp
index a0ca94ac2dcc005b403180aa11407ff7b33dcbc6..a71a4279bb9bf3cc5485c7fb085bc1a1382951cc 100644
--- a/Tools/MiniBrowser/wpe/main.cpp
+++ b/Tools/MiniBrowser/wpe/main.cpp
@@ -25,7 +25,7 @@
 
 #include "cmakeconfig.h"
 
-#include "HeadlessViewBackend.h"
+#include "NullViewBackend.h"
 #include "WindowViewBackend.h"
 #if ENABLE_WEB_AUDIO || ENABLE_VIDEO
 #include <gst/gst.h>
@@ -43,6 +43,9 @@ static gboolean headlessMode;
 static gboolean privateMode;
 static gboolean automationMode;
 static gboolean ignoreTLSErrors;
+static gboolean inspectorPipe;
+static gboolean noStartupWindow;
+static const char* userDataDir;
 static const char* contentFilter;
 static const char* cookiesFile;
 static const char* cookiesPolicy;
@@ -63,6 +66,9 @@ static const GOptionEntry commandLineOptions[] =
     { "content-filter", 0, 0, G_OPTION_ARG_FILENAME, &contentFilter, "JSON with content filtering rules", "FILE" },
     { "bg-color", 0, 0, G_OPTION_ARG_STRING, &bgColor, "Window background color. Default: white", "COLOR" },
     { "version", 'v', 0, G_OPTION_ARG_NONE, &printVersion, "Print the WPE version", nullptr },
+    { "inspector-pipe", 'v', 0, G_OPTION_ARG_NONE, &inspectorPipe, "Expose remote debugging protocol over pipe", nullptr },
+    { "user-data-dir", 0, 0, G_OPTION_ARG_STRING, &userDataDir, "Default profile persistence folder location", "FILE" },
+    { "no-startup-window", 0, 0, G_OPTION_ARG_NONE, &noStartupWindow, "Do not open default page", nullptr },
     { G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &uriArguments, nullptr, "[URL]" },
     { nullptr, 0, 0, G_OPTION_ARG_NONE, nullptr, nullptr, nullptr }
 };
@@ -131,7 +137,7 @@ static gboolean decidePermissionRequest(WebKitWebView *, WebKitPermissionRequest
 static std::unique_ptr<WPEToolingBackends::ViewBackend> createViewBackend(uint32_t width, uint32_t height)
 {
     if (headlessMode)
-        return std::make_unique<WPEToolingBackends::HeadlessViewBackend>(width, height);
+        return std::make_unique<WPEToolingBackends::NullViewBackend>();
     return std::make_unique<WPEToolingBackends::WindowViewBackend>(width, height);
 }
 
@@ -147,12 +153,33 @@ static void filterSavedCallback(WebKitUserContentFilterStore *store, GAsyncResul
     g_main_loop_quit(data->mainLoop);
 }
 
+static gboolean webViewLoadFailed()
+{
+    return TRUE;
+}
+
 static void webViewClose(WebKitWebView* webView, gpointer)
 {
     g_object_unref(webView);
 }
 
-static WebKitWebView* createWebView(WebKitWebView* webView, WebKitNavigationAction*, gpointer)
+static gboolean scriptDialog(WebKitWebView*, WebKitScriptDialog* dialog, gpointer)
+{
+    if (inspectorPipe)
+        webkit_script_dialog_ref(dialog);
+    return TRUE;
+}
+
+static gboolean scriptDialogHandled(WebKitWebView*, WebKitScriptDialog* dialog, gpointer)
+{
+    if (inspectorPipe)
+        webkit_script_dialog_unref(dialog);
+    return TRUE;
+}
+
+static WebKitWebView* createWebView(WebKitWebView* webView, WebKitNavigationAction*, gpointer);
+
+static WebKitWebView* createWebViewImpl(WebKitWebView* webView, WebKitWebContext *webContext)
 {
     auto backend = createViewBackend(1280, 720);
     struct wpe_view_backend* wpeBackend = backend->backend();
@@ -164,14 +191,47 @@ static WebKitWebView* createWebView(WebKitWebView* webView, WebKitNavigationActi
             delete static_cast<WPEToolingBackends::ViewBackend*>(data);
         }, backend.release());
 
-    auto* newWebView = webkit_web_view_new_with_related_view(viewBackend, webView);
-    webkit_web_view_set_settings(newWebView, webkit_web_view_get_settings(webView));
+    WebKitWebView* newWebView;
+    if (webView) {
+        newWebView = webkit_web_view_new_with_related_view(viewBackend, webView);
+    } else {
+        newWebView = WEBKIT_WEB_VIEW(g_object_new(WEBKIT_TYPE_WEB_VIEW,
+            "backend", viewBackend,
+            "web-context", webContext,
+            nullptr));
+    }
 
     g_signal_connect(newWebView, "close", G_CALLBACK(webViewClose), nullptr);
-
+    g_signal_connect(newWebView, "load-failed", G_CALLBACK(webViewLoadFailed), nullptr);
+    g_signal_connect(newWebView, "script-dialog", G_CALLBACK(scriptDialog), nullptr);
+    g_signal_connect(newWebView, "script-dialog-handled", G_CALLBACK(scriptDialogHandled), nullptr);
+    g_signal_connect(newWebView, "create", G_CALLBACK(createWebView), nullptr);
     return newWebView;
 }
 
+static WebKitWebView* createWebView(WebKitWebView* webView, WebKitNavigationAction*, gpointer)
+{
+    return createWebViewImpl(webView, nullptr);
+}
+
+static WebKitWebContext *persistentWebContext = NULL;
+
+static WebKitWebView* createNewPage(WebKitBrowserInspector*, WebKitWebContext *webContext)
+{
+    if (!webContext)
+        webContext = persistentWebContext;
+    WebKitWebView* webView = createWebViewImpl(nullptr, webContext);
+    webkit_web_view_load_uri(webView, "about:blank");
+    return webView;
+}
+
+static void configureBrowserInspector(GMainLoop* mainLoop)
+{
+    WebKitBrowserInspector* browserInspector = webkit_browser_inspector_get_default();
+    g_signal_connect(browserInspector, "create-new-page", G_CALLBACK(createNewPage), NULL);
+    webkit_browser_inspector_initialize_pipe(mainLoop);
+}
+
 int main(int argc, char *argv[])
 {
 #if ENABLE_DEVELOPER_MODE
@@ -206,6 +266,14 @@ int main(int argc, char *argv[])
     }
 
     auto* loop = g_main_loop_new(nullptr, FALSE);
+    if (inspectorPipe)
+        configureBrowserInspector(loop);
+
+    if (noStartupWindow) {
+        g_main_loop_run(loop);
+        g_main_loop_unref(loop);
+        return 0;
+    }
 
     auto backend = createViewBackend(1280, 720);
     struct wpe_view_backend* wpeBackend = backend->backend();
@@ -215,7 +283,19 @@ int main(int argc, char *argv[])
         return 1;
     }
 
-    auto* webContext = (privateMode || automationMode) ? webkit_web_context_new_ephemeral() : webkit_web_context_get_default();
+    WebKitWebsiteDataManager *manager;
+    if (userDataDir) {
+        manager = webkit_website_data_manager_new("base-data-directory", userDataDir, "base-cache-directory", userDataDir, NULL);
+        cookiesFile = g_build_filename(userDataDir, "cookies.txt", NULL);
+    } else if (inspectorPipe || privateMode || automationMode) {
+        manager = webkit_website_data_manager_new_ephemeral();
+    } else {
+        manager = webkit_website_data_manager_new(NULL);
+    }
+
+    WebKitWebContext *webContext = WEBKIT_WEB_CONTEXT(g_object_new(WEBKIT_TYPE_WEB_CONTEXT, "website-data-manager", manager, "process-swap-on-cross-site-navigation-enabled", TRUE, NULL));
+    persistentWebContext = webContext;
+    g_object_unref(manager);
 
     if (cookiesPolicy) {
         auto* cookieManager = webkit_web_context_get_cookie_manager(webContext);
@@ -300,7 +380,9 @@ int main(int argc, char *argv[])
     g_signal_connect(webContext, "automation-started", G_CALLBACK(automationStartedCallback), webView);
     g_signal_connect(webView, "permission-request", G_CALLBACK(decidePermissionRequest), nullptr);
     g_signal_connect(webView, "create", G_CALLBACK(createWebView), nullptr);
-    g_signal_connect(webView, "close", G_CALLBACK(webViewClose), nullptr);
+    // FIXME(yurys): next line was added in https://trac.webkit.org/r256302 and causes
+    // use after free crashing in playwright. See https://webkit.org/b/207529#c7
+    // g_signal_connect(webView, "close", G_CALLBACK(webViewClose), nullptr);
 
     if (ignoreTLSErrors)
         webkit_web_context_set_tls_errors_policy(webContext, WEBKIT_TLS_ERRORS_POLICY_IGNORE);
@@ -319,7 +401,7 @@ int main(int argc, char *argv[])
         g_object_unref(file);
         webkit_web_view_load_uri(webView, url);
         g_free(url);
-    } else if (automationMode)
+    } else if (automationMode || inspectorPipe)
         webkit_web_view_load_uri(webView, "about:blank");
     else
         webkit_web_view_load_uri(webView, "https://wpewebkit.org");
@@ -327,8 +409,7 @@ int main(int argc, char *argv[])
     g_main_loop_run(loop);
 
     g_object_unref(webView);
-    if (privateMode || automationMode)
-        g_object_unref(webContext);
+    g_object_unref(webContext);
     g_main_loop_unref(loop);
 
     return 0;
diff --git a/Tools/Playwright/Configurations/Base.xcconfig b/Tools/Playwright/Configurations/Base.xcconfig
new file mode 100644
index 0000000000000000000000000000000000000000..fc61d5227c8608488514cbd92a28dc7c1c2efaf4
--- /dev/null
+++ b/Tools/Playwright/Configurations/Base.xcconfig
@@ -0,0 +1,87 @@
+// Copyright (C) 2010-2017 Apple Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions
+// are met:
+// 1. Redistributions of source code must retain the above copyright
+//    notice, this list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright
+//    notice, this list of conditions and the following disclaimer in the
+//    documentation and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+// PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+
+#include? "../../../../Internal/Configurations/HaveInternalSDK.xcconfig"
+#include "SDKVariant.xcconfig"
+
+USE_INTERNAL_SDK = $(USE_INTERNAL_SDK_$(CONFIGURATION));
+USE_INTERNAL_SDK_Production = YES;
+USE_INTERNAL_SDK_Debug = $(HAVE_INTERNAL_SDK);
+USE_INTERNAL_SDK_Release = $(HAVE_INTERNAL_SDK);
+
+GCC_PREPROCESSOR_DEFINITIONS = DISABLE_LEGACY_WEBKIT_DEPRECATIONS $(inherited);
+
+CLANG_CXX_LANGUAGE_STANDARD = gnu++1z;
+CLANG_CXX_LIBRARY = libc++;
+CLANG_ENABLE_OBJC_WEAK = YES;
+DEBUG_INFORMATION_FORMAT = dwarf-with-dsym;
+PREBINDING = NO
+GCC_C_LANGUAGE_STANDARD = gnu99
+GCC_ENABLE_CPP_EXCEPTIONS = NO;
+GCC_PRECOMPILE_PREFIX_HEADER = YES
+ENABLE_STRICT_OBJC_MSGSEND = YES;
+GCC_TREAT_WARNINGS_AS_ERRORS = YES
+CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
+CLANG_WARN_BOOL_CONVERSION = YES;
+CLANG_WARN_COMMA = YES;
+CLANG_WARN_CONSTANT_CONVERSION = YES;
+CLANG_WARN_EMPTY_BODY = YES;
+CLANG_WARN_ENUM_CONVERSION = YES;
+CLANG_WARN_INFINITE_RECURSION = YES;
+CLANG_WARN_INT_CONVERSION = YES;
+CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+CLANG_WARN_STRICT_PROTOTYPES = YES;
+CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
+CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+CLANG_WARN_SUSPICIOUS_MOVE = YES;
+CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
+CLANG_WARN_UNREACHABLE_CODE = YES;
+GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
+GCC_WARN_ABOUT_DEPRECATED_FUNCTIONS = NO;
+GCC_WARN_ABOUT_RETURN_TYPE = YES;
+GCC_WARN_UNINITIALIZED_AUTOS = YES;
+GCC_WARN_UNUSED_FUNCTION = YES
+GCC_WARN_UNUSED_VARIABLE = YES
+CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
+GCC_WARN_UNDECLARED_SELECTOR = YES;
+CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
+CLANG_ANALYZER_LOCALIZABILITY_NONLOCALIZED = YES;
+GCC_VERSION = com.apple.compilers.llvm.clang.1_0;
+WARNING_CFLAGS = -Wall -W -Wno-unused-parameter
+GCC_NO_COMMON_BLOCKS = YES;
+
+SUPPORTED_PLATFORMS = iphoneos iphonesimulator macosx tvos tvsimulator watchos watchsimulator;
+
+TARGET_MAC_OS_X_VERSION_MAJOR = $(TARGET_MAC_OS_X_VERSION_MAJOR$(MACOSX_DEPLOYMENT_TARGET:suffix:identifier));
+TARGET_MAC_OS_X_VERSION_MAJOR_13 = 101300;
+TARGET_MAC_OS_X_VERSION_MAJOR_14 = 101400;
+TARGET_MAC_OS_X_VERSION_MAJOR_15 = 101500;
+TARGET_MAC_OS_X_VERSION_MAJOR_16 = 101600;
+
+SDKROOT = macosx.internal;
+
+OTHER_CFLAGS = $(ASAN_OTHER_CFLAGS);
+OTHER_CPLUSPLUSFLAGS = $(ASAN_OTHER_CPLUSPLUSFLAGS);
+OTHER_LDFLAGS = $(ASAN_OTHER_LDFLAGS);
+
+CODE_SIGN_IDENTITY = -;
diff --git a/Tools/Playwright/Configurations/DebugRelease.xcconfig b/Tools/Playwright/Configurations/DebugRelease.xcconfig
new file mode 100644
index 0000000000000000000000000000000000000000..44dc1139c298bd119368ef4f45bbf0888dc71cdb
--- /dev/null
+++ b/Tools/Playwright/Configurations/DebugRelease.xcconfig
@@ -0,0 +1,45 @@
+// Copyright (C) 2010, 2013 Apple Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions
+// are met:
+// 1. Redistributions of source code must retain the above copyright
+//    notice, this list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright
+//    notice, this list of conditions and the following disclaimer in the
+//    documentation and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+// PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+
+#include "Base.xcconfig"
+
+ARCHS = $(ARCHS_STANDARD_32_64_BIT);
+
+ONLY_ACTIVE_ARCH = YES;
+
+TARGET_MAC_OS_X_VERSION_MAJOR = $(MAC_OS_X_VERSION_MAJOR);
+
+MACOSX_DEPLOYMENT_TARGET = $(MACOSX_DEPLOYMENT_TARGET_$(TARGET_MAC_OS_X_VERSION_MAJOR))
+MACOSX_DEPLOYMENT_TARGET_101300 = 10.13;
+MACOSX_DEPLOYMENT_TARGET_101400 = 10.14;
+MACOSX_DEPLOYMENT_TARGET_101500 = 10.15;
+MACOSX_DEPLOYMENT_TARGET_101600 = 10.16;
+
+GCC_WARN_ABOUT_DEPRECATED_FUNCTIONS = YES;
+
+SDKROOT = $(SDKROOT_$(USE_INTERNAL_SDK));
+SDKROOT_ = macosx;
+SDKROOT_YES = macosx.internal;
+
+WK_CCACHE_DIR = $(SRCROOT)/../ccache;
+#include "../../ccache/ccache.xcconfig"
diff --git a/Tools/Playwright/Configurations/Playwright.xcconfig b/Tools/Playwright/Configurations/Playwright.xcconfig
new file mode 100644
index 0000000000000000000000000000000000000000..d05c841a5b0f5fce481f16b8c98caf3a5846db77
--- /dev/null
+++ b/Tools/Playwright/Configurations/Playwright.xcconfig
@@ -0,0 +1,30 @@
+// Copyright (C) 2010 Apple Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions
+// are met:
+// 1. Redistributions of source code must retain the above copyright
+//    notice, this list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright
+//    notice, this list of conditions and the following disclaimer in the
+//    documentation and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+// PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+
+PRODUCT_NAME = Playwright
+PRODUCT_BUNDLE_IDENTIFIER = org.webkit.$(PRODUCT_NAME:rfc1034identifier)
+GCC_PREFIX_HEADER = mac/Playwright_Prefix.pch
+INFOPLIST_FILE = mac/Info.plist
+EXCLUDED_SOURCE_FILE_NAMES[sdk=iphone*] = *
+OTHER_LDFLAGS[sdk=macosx*] = $(inherited) -framework Cocoa -framework WebKit
+STRIP_STYLE = debugging;
diff --git a/Tools/Playwright/Configurations/SDKVariant.xcconfig b/Tools/Playwright/Configurations/SDKVariant.xcconfig
new file mode 100644
index 0000000000000000000000000000000000000000..fcdf7e65a67c61fb19ef19c428652f336c180e8e
--- /dev/null
+++ b/Tools/Playwright/Configurations/SDKVariant.xcconfig
@@ -0,0 +1,45 @@
+// Copyright (C) 2019 Apple Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions
+// are met:
+// 1. Redistributions of source code must retain the above copyright
+//    notice, this list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright
+//    notice, this list of conditions and the following disclaimer in the
+//    documentation and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+// PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+WK_EMPTY_ = YES;
+WK_NOT_ = YES;
+WK_NOT_YES = NO;
+
+WK_ALTERNATE_FRAMEWORKS_DIR = $(WK_ALTERNATE_FRAMEWORKS_DIR_$(SDK_VARIANT));
+WK_ALTERNATE_FRAMEWORKS_DIR_iosmac = /System/iOSSupport;
+WK_USE_ALTERNATE_FRAMEWORKS_DIR = $(WK_NOT_$(WK_EMPTY_$(WK_ALTERNATE_FRAMEWORKS_DIR)));
+
+WK_ALTERNATE_PLATFORM_NAME = $(WK_ALTERNATE_PLATFORM_NAME_$(SDK_VARIANT));
+WK_ALTERNATE_PLATFORM_NAME_iosmac = maccatalyst;
+WK_USE_ALTERNATE_PLATFORM_NAME = $(WK_NOT_$(WK_EMPTY_$(WK_ALTERNATE_PLATFORM_NAME)));
+
+WK_ALTERNATE_WEBKIT_SDK_PATH = $(WK_ALTERNATE_WEBKIT_SDK_PATH_$(WK_USE_ALTERNATE_FRAMEWORKS_DIR));
+WK_ALTERNATE_WEBKIT_SDK_PATH_YES = $(WK_ALTERNATE_FRAMEWORKS_DIR)/;
+
+WK_PLATFORM_NAME = $(WK_PLATFORM_NAME_ALTERNATE_$(WK_USE_ALTERNATE_PLATFORM_NAME));
+WK_PLATFORM_NAME_ALTERNATE_YES = $(WK_ALTERNATE_PLATFORM_NAME);
+WK_PLATFORM_NAME_ALTERNATE_NO = $(PLATFORM_NAME);
+
+EFFECTIVE_PLATFORM_NAME = $(EFFECTIVE_PLATFORM_NAME_ALTERNATE_$(WK_USE_ALTERNATE_PLATFORM_NAME));
+EFFECTIVE_PLATFORM_NAME_ALTERNATE_YES = -$(WK_ALTERNATE_PLATFORM_NAME);
+EFFECTIVE_PLATFORM_NAME_ALTERNATE_NO = $(EFFECTIVE_PLATFORM_NAME);
diff --git a/Tools/Playwright/MBToolbarItem.h b/Tools/Playwright/MBToolbarItem.h
new file mode 100644
index 0000000000000000000000000000000000000000..9971d4c1023a9f6e57c6058ae20729e51bb6d503
--- /dev/null
+++ b/Tools/Playwright/MBToolbarItem.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+@interface MBToolbarItem : NSToolbarItem
+@end
diff --git a/Tools/Playwright/MBToolbarItem.m b/Tools/Playwright/MBToolbarItem.m
new file mode 100644
index 0000000000000000000000000000000000000000..56f777891519e820105ae50a86141a534ec4794b
--- /dev/null
+++ b/Tools/Playwright/MBToolbarItem.m
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "MBToolbarItem.h"
+
+@implementation MBToolbarItem
+
+- (void)validate
+{
+    [self setEnabled:[[self target] validateUserInterfaceItem:self]];
+}
+
+@end
diff --git a/Tools/Playwright/Makefile b/Tools/Playwright/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..58e52428388d927ae7681d999e6dd28e0fb3ec6b
--- /dev/null
+++ b/Tools/Playwright/Makefile
@@ -0,0 +1,21 @@
+# Build Playwright only on SnowLeopard and later.
+
+OSX_VERSION ?= $(shell sw_vers -productVersion | cut -d. -f 2)
+BUILD_PLAYWRIGHT = $(shell (( $(OSX_VERSION) >= 6 )) && echo "YES" )
+
+ifeq "$(BUILD_PLAYWRIGHT)" "YES"
+
+SCRIPTS_PATH = ../Scripts
+include ../../Makefile.shared
+
+else
+
+all: ;
+
+debug d development dev develop: ;
+
+release r deployment dep deploy: ;
+
+clean: ;
+
+endif
diff --git a/Tools/Playwright/Playwright.xcodeproj/project.pbxproj b/Tools/Playwright/Playwright.xcodeproj/project.pbxproj
new file mode 100644
index 0000000000000000000000000000000000000000..75a945e72d9fcad94bb89fc6325df18d3259383d
--- /dev/null
+++ b/Tools/Playwright/Playwright.xcodeproj/project.pbxproj
@@ -0,0 +1,264 @@
+// !$*UTF8*$!
+{
+	archiveVersion = 1;
+	classes = {
+	};
+	objectVersion = 46;
+	objects = {
+
+/* Begin PBXBuildFile section */
+		256AC3DA0F4B6AC300CF336A /* AppDelegate.m in Sources */ = {isa = PBXBuildFile; fileRef = 256AC3D90F4B6AC300CF336A /* AppDelegate.m */; };
+		51E244FA11EFCE07008228D2 /* MBToolbarItem.m in Sources */ = {isa = PBXBuildFile; fileRef = 51E244F911EFCE07008228D2 /* MBToolbarItem.m */; };
+		BC329487116A92E2008635D1 /* main.m in Sources */ = {isa = PBXBuildFile; fileRef = BC329486116A92E2008635D1 /* main.m */; };
+		BC329498116A941B008635D1 /* BrowserWindowController.m in Sources */ = {isa = PBXBuildFile; fileRef = BC329497116A941B008635D1 /* BrowserWindowController.m */; };
+		BC72B89511E57E07001EB4EB /* MainMenu.xib in Resources */ = {isa = PBXBuildFile; fileRef = 1DDD58150DA1D0A300B3202A /* MainMenu.xib */; };
+		BC72B89611E57E0F001EB4EB /* BrowserWindow.xib in Resources */ = {isa = PBXBuildFile; fileRef = BC3294A2116A9852008635D1 /* BrowserWindow.xib */; };
+/* End PBXBuildFile section */
+
+/* Begin PBXFileReference section */
+		1AFFEF761860EE6800DA465F /* Cocoa.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Cocoa.framework; path = System/Library/Frameworks/Cocoa.framework; sourceTree = SDKROOT; };
+		1AFFEF781860EE6800DA465F /* CoreData.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = CoreData.framework; path = System/Library/Frameworks/CoreData.framework; sourceTree = SDKROOT; };
+		1DDD58150DA1D0A300B3202A /* MainMenu.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; name = MainMenu.xib; path = mac/MainMenu.xib; sourceTree = "<group>"; };
+		256AC3D80F4B6AC300CF336A /* AppDelegate.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = AppDelegate.h; path = mac/AppDelegate.h; sourceTree = "<group>"; };
+		256AC3D90F4B6AC300CF336A /* AppDelegate.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = AppDelegate.m; path = mac/AppDelegate.m; sourceTree = "<group>"; };
+		256AC3F00F4B6AF500CF336A /* Playwright_Prefix.pch */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = Playwright_Prefix.pch; path = mac/Playwright_Prefix.pch; sourceTree = "<group>"; };
+		29B97324FDCFA39411CA2CEB /* AppKit.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = AppKit.framework; path = /System/Library/Frameworks/AppKit.framework; sourceTree = "<absolute>"; };
+		29B97325FDCFA39411CA2CEB /* Foundation.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Foundation.framework; path = /System/Library/Frameworks/Foundation.framework; sourceTree = "<absolute>"; };
+		37BAF90620218053000EA87A /* Playwright.entitlements */ = {isa = PBXFileReference; lastKnownFileType = text.plist.entitlements; path = Playwright.entitlements; sourceTree = "<group>"; };
+		51E244F811EFCE07008228D2 /* MBToolbarItem.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MBToolbarItem.h; sourceTree = "<group>"; };
+		51E244F911EFCE07008228D2 /* MBToolbarItem.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MBToolbarItem.m; sourceTree = "<group>"; };
+		8D1107320486CEB800E47091 /* Playwright.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Playwright.app; sourceTree = BUILT_PRODUCTS_DIR; };
+		A1B89B95221E027A00EB4CEB /* SDKVariant.xcconfig */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.xcconfig; path = SDKVariant.xcconfig; sourceTree = "<group>"; };
+		BC329486116A92E2008635D1 /* main.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = main.m; path = mac/main.m; sourceTree = "<group>"; };
+		BC329496116A941B008635D1 /* BrowserWindowController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = BrowserWindowController.h; path = mac/BrowserWindowController.h; sourceTree = "<group>"; };
+		BC329497116A941B008635D1 /* BrowserWindowController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = BrowserWindowController.m; path = mac/BrowserWindowController.m; sourceTree = "<group>"; };
+		BC3294A2116A9852008635D1 /* BrowserWindow.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; name = BrowserWindow.xib; path = mac/BrowserWindow.xib; sourceTree = "<group>"; };
+		BC72B89A11E57E8A001EB4EB /* Info.plist */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.xml; name = Info.plist; path = mac/Info.plist; sourceTree = "<group>"; };
+		BCA8CBDD11E578A000812FB8 /* Base.xcconfig */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.xcconfig; path = Base.xcconfig; sourceTree = "<group>"; };
+		BCA8CBDE11E578A000812FB8 /* DebugRelease.xcconfig */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.xcconfig; path = DebugRelease.xcconfig; sourceTree = "<group>"; };
+		BCA8CBDF11E578A000812FB8 /* Playwright.xcconfig */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.xcconfig; path = Playwright.xcconfig; sourceTree = "<group>"; };
+/* End PBXFileReference section */
+
+/* Begin PBXFrameworksBuildPhase section */
+		8D11072E0486CEB800E47091 /* Frameworks */ = {
+			isa = PBXFrameworksBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+/* End PBXFrameworksBuildPhase section */
+
+/* Begin PBXGroup section */
+		080E96DDFE201D6D7F000002 /* Playwright */ = {
+			isa = PBXGroup;
+			children = (
+				256AC3D80F4B6AC300CF336A /* AppDelegate.h */,
+				256AC3D90F4B6AC300CF336A /* AppDelegate.m */,
+				BC72B89A11E57E8A001EB4EB /* Info.plist */,
+				BC329486116A92E2008635D1 /* main.m */,
+				51E244F811EFCE07008228D2 /* MBToolbarItem.h */,
+				51E244F911EFCE07008228D2 /* MBToolbarItem.m */,
+				37BAF90620218053000EA87A /* Playwright.entitlements */,
+				BC329496116A941B008635D1 /* BrowserWindowController.h */,
+				BC329497116A941B008635D1 /* BrowserWindowController.m */,
+			);
+			name = Playwright;
+			sourceTree = "<group>";
+		};
+		1058C7A2FEA54F0111CA2CBC /* Other Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				29B97324FDCFA39411CA2CEB /* AppKit.framework */,
+				1AFFEF781860EE6800DA465F /* CoreData.framework */,
+				29B97325FDCFA39411CA2CEB /* Foundation.framework */,
+			);
+			name = "Other Frameworks";
+			sourceTree = "<group>";
+		};
+		19C28FACFE9D520D11CA2CBC /* Products */ = {
+			isa = PBXGroup;
+			children = (
+				8D1107320486CEB800E47091 /* Playwright.app */,
+			);
+			name = Products;
+			sourceTree = "<group>";
+		};
+		29B97314FDCFA39411CA2CEB /* Playwright */ = {
+			isa = PBXGroup;
+			children = (
+				256AC3F00F4B6AF500CF336A /* Playwright_Prefix.pch */,
+				080E96DDFE201D6D7F000002 /* Playwright */,
+				29B97317FDCFA39411CA2CEB /* Resources */,
+				BCA8CBDA11E5787800812FB8 /* Configurations */,
+				29B97323FDCFA39411CA2CEB /* Frameworks */,
+				19C28FACFE9D520D11CA2CBC /* Products */,
+			);
+			name = Playwright;
+			sourceTree = "<group>";
+		};
+		29B97317FDCFA39411CA2CEB /* Resources */ = {
+			isa = PBXGroup;
+			children = (
+				BC3294A2116A9852008635D1 /* BrowserWindow.xib */,
+				1DDD58150DA1D0A300B3202A /* MainMenu.xib */,
+			);
+			name = Resources;
+			sourceTree = "<group>";
+		};
+		29B97323FDCFA39411CA2CEB /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				1058C7A2FEA54F0111CA2CBC /* Other Frameworks */,
+				1AFFEF761860EE6800DA465F /* Cocoa.framework */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
+		BCA8CBDA11E5787800812FB8 /* Configurations */ = {
+			isa = PBXGroup;
+			children = (
+				BCA8CBDD11E578A000812FB8 /* Base.xcconfig */,
+				BCA8CBDE11E578A000812FB8 /* DebugRelease.xcconfig */,
+				BCA8CBDF11E578A000812FB8 /* Playwright.xcconfig */,
+				A1B89B95221E027A00EB4CEB /* SDKVariant.xcconfig */,
+			);
+			path = Configurations;
+			sourceTree = "<group>";
+		};
+/* End PBXGroup section */
+
+/* Begin PBXNativeTarget section */
+		8D1107260486CEB800E47091 /* Playwright */ = {
+			isa = PBXNativeTarget;
+			buildConfigurationList = C01FCF4A08A954540054247C /* Build configuration list for PBXNativeTarget "Playwright" */;
+			buildPhases = (
+				8D1107290486CEB800E47091 /* Resources */,
+				8D11072C0486CEB800E47091 /* Sources */,
+				8D11072E0486CEB800E47091 /* Frameworks */,
+			);
+			buildRules = (
+			);
+			dependencies = (
+			);
+			name = Playwright;
+			productInstallPath = "$(HOME)/Applications";
+			productName = Playwright;
+			productReference = 8D1107320486CEB800E47091 /* Playwright.app */;
+			productType = "com.apple.product-type.application";
+		};
+/* End PBXNativeTarget section */
+
+/* Begin PBXProject section */
+		29B97313FDCFA39411CA2CEC /* Project object */ = {
+			isa = PBXProject;
+			attributes = {
+				LastSwiftUpdateCheck = 0700;
+				LastUpgradeCheck = 1000;
+				TargetAttributes = {
+					8D1107260486CEB800E47091 = {
+						SystemCapabilities = {
+							com.apple.Sandbox = {
+								enabled = 1;
+							};
+						};
+					};
+				};
+			};
+			buildConfigurationList = C01FCF4E08A954540054247B /* Build configuration list for PBXProject "Playwright" */;
+			compatibilityVersion = "Xcode 3.2";
+			developmentRegion = en;
+			hasScannedForEncodings = 1;
+			knownRegions = (
+				en,
+			);
+			mainGroup = 29B97314FDCFA39411CA2CEB /* Playwright */;
+			projectDirPath = "";
+			projectRoot = "";
+			targets = (
+				8D1107260486CEB800E47091 /* Playwright */,
+			);
+		};
+/* End PBXProject section */
+
+/* Begin PBXResourcesBuildPhase section */
+		8D1107290486CEB800E47091 /* Resources */ = {
+			isa = PBXResourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				BC72B89611E57E0F001EB4EB /* BrowserWindow.xib in Resources */,
+				BC72B89511E57E07001EB4EB /* MainMenu.xib in Resources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+/* End PBXResourcesBuildPhase section */
+
+/* Begin PBXSourcesBuildPhase section */
+		8D11072C0486CEB800E47091 /* Sources */ = {
+			isa = PBXSourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				256AC3DA0F4B6AC300CF336A /* AppDelegate.m in Sources */,
+				BC329487116A92E2008635D1 /* main.m in Sources */,
+				51E244FA11EFCE07008228D2 /* MBToolbarItem.m in Sources */,
+				BC329498116A941B008635D1 /* BrowserWindowController.m in Sources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+/* End PBXSourcesBuildPhase section */
+
+/* Begin XCBuildConfiguration section */
+		C01FCF4B08A954540054247C /* Debug */ = {
+			isa = XCBuildConfiguration;
+			baseConfigurationReference = BCA8CBDF11E578A000812FB8 /* Playwright.xcconfig */;
+			buildSettings = {
+			};
+			name = Debug;
+		};
+		C01FCF4C08A954540054247B /* Release */ = {
+			isa = XCBuildConfiguration;
+			baseConfigurationReference = BCA8CBDF11E578A000812FB8 /* Playwright.xcconfig */;
+			buildSettings = {
+			};
+			name = Release;
+		};
+		C01FCF4F08A954540054247C /* Debug */ = {
+			isa = XCBuildConfiguration;
+			baseConfigurationReference = BCA8CBDE11E578A000812FB8 /* DebugRelease.xcconfig */;
+			buildSettings = {
+				GCC_OPTIMIZATION_LEVEL = 0;
+			};
+			name = Debug;
+		};
+		C01FCF5008A954540054247C /* Release */ = {
+			isa = XCBuildConfiguration;
+			baseConfigurationReference = BCA8CBDE11E578A000812FB8 /* DebugRelease.xcconfig */;
+			buildSettings = {
+			};
+			name = Release;
+		};
+/* End XCBuildConfiguration section */
+
+/* Begin XCConfigurationList section */
+		C01FCF4A08A954540054247C /* Build configuration list for PBXNativeTarget "Playwright" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				C01FCF4B08A954540054247C /* Debug */,
+				C01FCF4C08A954540054247B /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
+		C01FCF4E08A954540054247B /* Build configuration list for PBXProject "Playwright" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				C01FCF4F08A954540054247C /* Debug */,
+				C01FCF5008A954540054247C /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
+/* End XCConfigurationList section */
+	};
+	rootObject = 29B97313FDCFA39411CA2CEC /* Project object */;
+}
diff --git a/Tools/Playwright/Playwright.xcodeproj/xcshareddata/xcschemes/Playwright.xcscheme b/Tools/Playwright/Playwright.xcodeproj/xcshareddata/xcschemes/Playwright.xcscheme
new file mode 100644
index 0000000000000000000000000000000000000000..00fb6b0006c743091a8bbf8edb18b21192ea7d6c
--- /dev/null
+++ b/Tools/Playwright/Playwright.xcodeproj/xcshareddata/xcschemes/Playwright.xcscheme
@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1140"
+   version = "1.3">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "8D1107260486CEB800E47090"
+               BuildableName = "Playwright.app"
+               BlueprintName = "Playwright"
+               ReferencedContainer = "container:Playwright.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <Testables>
+      </Testables>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "8D1107260486CEB800E47090"
+            BuildableName = "Playwright.app"
+            BlueprintName = "Playwright"
+            ReferencedContainer = "container:Playwright.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "8D1107260486CEB800E47090"
+            BuildableName = "Playwright.app"
+            BlueprintName = "Playwright"
+            ReferencedContainer = "container:Playwright.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>
diff --git a/Tools/Playwright/mac/AppDelegate.h b/Tools/Playwright/mac/AppDelegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..86e7b0c64df5fccdd66b87eecd995e0a10d57b83
--- /dev/null
+++ b/Tools/Playwright/mac/AppDelegate.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import <WebKit/_WKBrowserInspector.h>
+
+@interface WebViewDialog : NSObject
+@property (nonatomic, strong) WKWebView *webView;
+@property (nonatomic, copy) void (^completionHandler)(BOOL accept, NSString* value);
+@end
+
+@interface BrowserAppDelegate : NSObject <NSApplicationDelegate, WKUIDelegate, _WKBrowserInspectorDelegate> {
+    NSMutableSet *_browserWindowControllers;
+    NSMutableSet *_headlessWindows;
+    NSMutableSet *_browserContexts;
+    bool _headless;
+    bool _noStartupWindow;
+    NSMutableSet *_dialogs;
+    NSString* _initialURL;
+    NSString* _userDataDir;
+    IBOutlet NSMenuItem *_newWebKit2WindowItem;
+}
+
+- (void)browserWindowWillClose:(NSWindow *)window;
+
+@end
+
+@interface NSApplication (PlaywrightApplicationExtensions)
+
+- (BrowserAppDelegate *)browserAppDelegate;
+
+@end
diff --git a/Tools/Playwright/mac/AppDelegate.m b/Tools/Playwright/mac/AppDelegate.m
new file mode 100644
index 0000000000000000000000000000000000000000..144bb42f13cc92a5ddd91417cbef2512613bd27c
--- /dev/null
+++ b/Tools/Playwright/mac/AppDelegate.m
@@ -0,0 +1,401 @@
+/*
+ * Copyright (C) 2010-2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "AppDelegate.h"
+
+#import "BrowserWindowController.h"
+#import <WebKit/WKPreferencesPrivate.h>
+#import <WebKit/WKProcessPoolPrivate.h>
+#import <WebKit/WKUserContentControllerPrivate.h>
+#import <WebKit/WKWebViewConfigurationPrivate.h>
+#import <WebKit/WKWebViewPrivate.h>
+#import <WebKit/WKWebsiteDataStorePrivate.h>
+#import <WebKit/WebNSURLExtras.h>
+#import <WebKit/WebKit.h>
+#import <WebKit/_WKExperimentalFeature.h>
+#import <WebKit/_WKInternalDebugFeature.h>
+#import <WebKit/_WKProcessPoolConfiguration.h>
+#import <WebKit/_WKWebsiteDataStoreConfiguration.h>
+
+@implementation NSApplication (PlaywrightApplicationExtensions)
+
+- (BrowserAppDelegate *)browserAppDelegate
+{
+    return (BrowserAppDelegate *)[self delegate];
+}
+
+@end
+
+@interface NSApplication (TouchBar)
+@property (getter=isAutomaticCustomizeTouchBarMenuItemEnabled) BOOL automaticCustomizeTouchBarMenuItemEnabled;
+
+@property (readonly, nonatomic) WKWebViewConfiguration *defaultConfiguration;
+
+@end
+
+@implementation WebViewDialog
+- (void)dealloc
+{
+    [_webView release];
+    _webView = nil;
+    [super dealloc];
+}
+@end
+
+enum {
+    _NSBackingStoreUnbuffered = 3
+};
+
+NSString* const ActivityReason = @"Batch headless process";
+const NSActivityOptions ActivityOptions =
+    (NSActivityUserInitiatedAllowingIdleSystemSleep |
+     NSActivityLatencyCritical) &
+    ~(NSActivitySuddenTerminationDisabled |
+    NSActivityAutomaticTerminationDisabled);
+
+@implementation BrowserAppDelegate
+
+- (id)init
+{
+    self = [super init];
+    if (!self)
+        return nil;
+
+    _initialURL = nil;
+    _userDataDir = nil;
+    NSArray *arguments = [[NSProcessInfo processInfo] arguments];
+    NSRange subargs = NSMakeRange(1, [arguments count] - 1);
+    NSArray *subArray = [arguments subarrayWithRange:subargs];
+
+    for (NSString *argument in subArray) {
+        if (![argument hasPrefix:@"--"])
+            _initialURL = argument;
+        if ([argument hasPrefix:@"--user-data-dir="]) {
+            NSRange range = NSMakeRange(16, [argument length] - 16);
+            _userDataDir = [[argument substringWithRange:range] copy];
+        }
+    }
+
+    _headless = [arguments containsObject: @"--headless"];
+    _noStartupWindow = [arguments containsObject: @"--no-startup-window"];
+    _browserContexts = [[NSMutableSet alloc] init];
+
+    if (_headless) {
+        _headlessWindows = [[NSMutableSet alloc] init];
+        [NSApp setActivationPolicy:NSApplicationActivationPolicyAccessory];
+        [[NSProcessInfo processInfo] beginActivityWithOptions:ActivityOptions
+                                                       reason:ActivityReason];
+        _dialogs = [[NSMutableSet alloc] init];
+    } else {
+        [NSApp activateIgnoringOtherApps:YES];
+        _browserWindowControllers = [[NSMutableSet alloc] init];
+    }
+    if ([arguments containsObject: @"--inspector-pipe"])
+        [_WKBrowserInspector initializeRemoteInspectorPipe:self headless:_headless];
+    return self;
+}
+
+- (void)awakeFromNib
+{
+    if ([NSApp respondsToSelector:@selector(setAutomaticCustomizeTouchBarMenuItemEnabled:)])
+        [NSApp setAutomaticCustomizeTouchBarMenuItemEnabled:YES];
+}
+
+- (WKWebsiteDataStore *)persistentDataStore
+{
+    static WKWebsiteDataStore *dataStore;
+
+    if (!dataStore) {
+        _WKWebsiteDataStoreConfiguration *configuration = [[[_WKWebsiteDataStoreConfiguration alloc] init] autorelease];
+        if (_userDataDir) {
+            NSURL *cookieFile = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/cookie.db", _userDataDir]];
+            [configuration _setCookieStorageFile:cookieFile];
+
+            NSURL *applicationCacheDirectory = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/ApplicationCache", _userDataDir]];
+            [configuration setApplicationCacheDirectory:applicationCacheDirectory];
+
+            NSURL *cacheStorageDirectory = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/CacheStorage", _userDataDir]];
+            [configuration _setCacheStorageDirectory:cacheStorageDirectory];
+
+            NSURL *indexedDBDirectory = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/IndexedDB", _userDataDir]];
+            [configuration _setIndexedDBDatabaseDirectory:indexedDBDirectory];
+
+            NSURL *localStorageDirectory = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/LocalStorage", _userDataDir]];
+            [configuration _setWebStorageDirectory:localStorageDirectory];
+
+            NSURL *mediaCacheDirectory = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/MediaCache", _userDataDir]];
+            [configuration setMediaCacheDirectory:mediaCacheDirectory];
+
+            NSURL *mediaKeysDirectory = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/MediaKeys", _userDataDir]];
+            [configuration setMediaKeysStorageDirectory:mediaKeysDirectory];
+
+            NSURL *networkCacheDirectory = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/NetworkCache", _userDataDir]];
+            [configuration setNetworkCacheDirectory:networkCacheDirectory];
+
+            NSURL *loadStatsDirectory = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/ResourceLoadStatistics", _userDataDir]];
+            [configuration _setResourceLoadStatisticsDirectory:loadStatsDirectory];
+
+            NSURL *serviceWorkersDirectory = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/ServiceWorkers", _userDataDir]];
+            [configuration _setServiceWorkerRegistrationDirectory:serviceWorkersDirectory];
+
+            NSURL *webSqlDirectory = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/WebSQL", _userDataDir]];
+            [configuration _setWebSQLDatabaseDirectory:webSqlDirectory];
+        }
+        dataStore = [[WKWebsiteDataStore alloc] _initWithConfiguration:configuration];
+    }
+
+    return dataStore;
+}
+
+- (WKWebViewConfiguration *)defaultConfiguration
+{
+    static WKWebViewConfiguration *configuration;
+
+    if (!configuration) {
+        configuration = [[WKWebViewConfiguration alloc] init];
+        configuration.websiteDataStore = [self persistentDataStore];
+        configuration.preferences._fullScreenEnabled = YES;
+        configuration.preferences._developerExtrasEnabled = YES;
+        configuration.preferences._mediaDevicesEnabled = YES;
+        configuration.preferences._mockCaptureDevicesEnabled = YES;
+        configuration.preferences._hiddenPageDOMTimerThrottlingEnabled = NO;
+        configuration.preferences._hiddenPageDOMTimerThrottlingAutoIncreases = NO;
+        configuration.preferences._pageVisibilityBasedProcessSuppressionEnabled = NO;
+        configuration.preferences._domTimersThrottlingEnabled = NO;
+        configuration.preferences._requestAnimationFrameEnabled = YES;
+        _WKProcessPoolConfiguration *processConfiguration = [[[_WKProcessPoolConfiguration alloc] init] autorelease];
+        processConfiguration.forceOverlayScrollbars = YES;
+        configuration.processPool = [[[WKProcessPool alloc] _initWithConfiguration:processConfiguration AndDataStore:configuration.websiteDataStore] autorelease];
+    }
+    return configuration;
+}
+
+- (BrowserWindowController *)createBrowserWindowController:(id)sender
+{
+    if (_headless)
+        return nil;
+
+    BrowserWindowController *controller = [[[BrowserWindowController alloc] initWithConfiguration:[self defaultConfiguration]] autorelease];
+    if (!controller)
+        return nil;
+    [_browserWindowControllers addObject:controller];
+    return controller;
+}
+
+- (void)browserWindowWillClose:(NSWindow *)window
+{
+    [_browserWindowControllers removeObject:window.windowController];
+}
+
+- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
+{
+    if (!_headless)
+        [self _updateNewWindowKeyEquivalents];
+
+    if (_noStartupWindow)
+        return;
+
+    [self createNewPage:0];
+    _initialURL = nil;
+}
+
+- (BrowserWindowController *)frontmostBrowserWindowController
+{
+    for (NSWindow* window in [NSApp windows]) {
+        id delegate = [window delegate];
+
+        if (![delegate isKindOfClass:[BrowserWindowController class]])
+            continue;
+
+        BrowserWindowController *controller = (BrowserWindowController *)delegate;
+        assert([_browserWindowControllers containsObject:controller]);
+        return controller;
+    }
+
+    return nil;
+}
+
+- (void)_updateNewWindowKeyEquivalents
+{
+    NSString *normalWindowEquivalent = @"n";
+    _newWebKit2WindowItem.keyEquivalentModifierMask = NSEventModifierFlagCommand;
+    _newWebKit2WindowItem.keyEquivalent = normalWindowEquivalent;
+}
+
+#pragma mark WKBrowserInspectorDelegate
+
+- (WKWebViewConfiguration *) sessionConfiguration:(uint64_t)sessionID
+{
+    for (_WKBrowserContext *browserContext in _browserContexts) {
+        if ([[browserContext dataStore] sessionID] != sessionID)
+            continue;
+        WKWebViewConfiguration *configuration = [[[self defaultConfiguration] copy] autorelease];
+        configuration.websiteDataStore = [browserContext dataStore];
+        configuration.processPool = [browserContext processPool];
+        return configuration;
+    }
+    return [self defaultConfiguration];
+}
+
+- (WKWebView *)createNewPage:(uint64_t)sessionID
+{
+    NSString* urlString = _initialURL ? _initialURL : @"about:blank";
+    WKWebViewConfiguration *configuration = [self sessionConfiguration:sessionID];
+    if (_headless)
+        return [self createHeadlessPage:configuration withURL:urlString];
+    return [self createHeadfulPage:configuration withURL:urlString];
+}
+
+- (WKWebView *)createHeadfulPage:(WKWebViewConfiguration *)configuration withURL:(NSString*)urlString
+{
+
+    BrowserWindowController *controller = [[[BrowserWindowController alloc] initWithConfiguration:configuration] autorelease];
+    if (!controller)
+        return nil;
+    [[controller window] makeKeyAndOrderFront:nil];
+    [_browserWindowControllers addObject:controller];
+    [controller loadURLString:urlString];
+    return [controller webView];
+}
+
+- (WKWebView *)createHeadlessPage:(WKWebViewConfiguration *)configuration withURL:(NSString*)urlString
+{
+    NSRect rect = NSMakeRect(0, 0, 1024, 768);
+    NSScreen *firstScreen = [[NSScreen screens] objectAtIndex:0];
+    NSRect windowRect = NSOffsetRect(rect, -10000, [firstScreen frame].size.height - rect.size.height + 10000);
+    NSWindow* window = [[NSWindow alloc] initWithContentRect:windowRect styleMask:NSWindowStyleMaskBorderless backing:(NSBackingStoreType)_NSBackingStoreUnbuffered defer:YES];
+
+    WKWebView* webView = [[WKWebView alloc] initWithFrame:[window.contentView bounds] configuration:configuration];
+    webView._windowOcclusionDetectionEnabled = NO;
+    if (!webView)
+        return nil;
+
+    webView.autoresizingMask = NSViewWidthSizable | NSViewHeightSizable;
+    [window.contentView addSubview:webView];
+    if (urlString) {
+        NSURL *url = [NSURL _webkit_URLWithUserTypedString:urlString];
+        [webView loadRequest:[NSURLRequest requestWithURL:url]];
+    }
+    [_headlessWindows addObject:window];
+    webView.UIDelegate = self;
+    return [webView autorelease];
+}
+
+- (_WKBrowserContext *)createBrowserContext
+{
+    _WKBrowserContext *browserContext = [[_WKBrowserContext alloc] init];
+    _WKProcessPoolConfiguration *processConfiguration = [[[_WKProcessPoolConfiguration alloc] init] autorelease];
+    processConfiguration.forceOverlayScrollbars = YES;
+    browserContext.dataStore = [WKWebsiteDataStore nonPersistentDataStore];
+    browserContext.processPool = [[[WKProcessPool alloc] _initWithConfiguration:processConfiguration] autorelease];
+    [_browserContexts addObject:browserContext];
+    return browserContext;
+}
+
+- (void)deleteBrowserContext:(uint64_t)sessionID
+{
+    for (_WKBrowserContext *browserContext in _browserContexts) {
+        if ([[browserContext dataStore] sessionID] != sessionID)
+            continue;
+        [_browserContexts removeObject:browserContext];
+        return;
+    }
+}
+
+- (void)quit
+{
+    [NSApp performSelector:@selector(terminate:) withObject:nil afterDelay:0.0];
+}
+
+#pragma mark WKUIDelegate
+
+- (void)webViewDidClose:(WKWebView *)webView {
+    for (NSWindow *window in _headlessWindows) {
+        if (webView.window != window)
+            continue;
+        [webView removeFromSuperview];
+        [window close];
+        [_headlessWindows removeObject:window];
+        break;
+    }
+}
+
+- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler
+{
+    WebViewDialog* dialog = [[WebViewDialog alloc] autorelease];
+    dialog.webView = webView;
+    dialog.completionHandler = ^void (BOOL accept, NSString* value) {
+        completionHandler();
+    };
+    [_dialogs addObject:dialog];
+}
+
+- (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL result))completionHandler
+{
+    WebViewDialog* dialog = [[WebViewDialog alloc] autorelease];
+    dialog.webView = webView;
+    dialog.completionHandler = ^void (BOOL accept, NSString* value) {
+        completionHandler(accept);
+    };
+    [_dialogs addObject:dialog];
+}
+
+- (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString *result))completionHandler
+{
+    WebViewDialog* dialog = [[WebViewDialog alloc] autorelease];
+    dialog.webView = webView;
+    dialog.completionHandler = ^void (BOOL accept, NSString* value) {
+        completionHandler(accept && value ? value : nil);
+    };
+    [_dialogs addObject:dialog];
+}
+
+- (void)_webView:(WKWebView *)webView runBeforeUnloadConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL result))completionHandler
+{
+    WebViewDialog* dialog = [[WebViewDialog alloc] autorelease];
+    dialog.webView = webView;
+    dialog.completionHandler = ^void (BOOL accept, NSString* value) {
+        completionHandler(accept);
+    };
+    [_dialogs addObject:dialog];
+}
+
+- (void)webView:(WKWebView *)webView handleJavaScriptDialog:(BOOL)accept value:(NSString *)value
+{
+    for (WebViewDialog *dialog in _dialogs) {
+        if (dialog.webView != webView)
+            continue;
+        dialog.completionHandler(accept, value);
+        [_dialogs removeObject:dialog];
+        break;
+    }
+}
+
+- (nullable WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWebViewConfiguration *)configuration forNavigationAction:(WKNavigationAction *)navigationAction windowFeatures:(WKWindowFeatures *)windowFeatures
+{
+    return [self createHeadlessPage:configuration withURL:nil];
+}
+
+@end
diff --git a/Tools/Playwright/mac/BrowserWindow.xib b/Tools/Playwright/mac/BrowserWindow.xib
new file mode 100644
index 0000000000000000000000000000000000000000..f6f3d8e3a0f163e61b2f3d54819e9d25a0a3eb75
--- /dev/null
+++ b/Tools/Playwright/mac/BrowserWindow.xib
@@ -0,0 +1,153 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="11191" systemVersion="16D17a" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none">
+    <dependencies>
+        <deployment identifier="macosx"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="11191"/>
+    </dependencies>
+    <objects>
+        <customObject id="-2" userLabel="File's Owner" customClass="BrowserWindowController">
+            <connections>
+                <outlet property="backButton" destination="40" id="46"/>
+                <outlet property="containerView" destination="9" id="37"/>
+                <outlet property="forwardButton" destination="42" id="47"/>
+                <outlet property="progressIndicator" destination="21" id="33"/>
+                <outlet property="reloadButton" destination="23" id="34"/>
+                <outlet property="share" destination="1hB-AH-eUl" id="si4-8e-DsM"/>
+                <outlet property="toggleUseShrinkToFitButton" destination="82" id="9w7-AB-Ye3"/>
+                <outlet property="toolbar" destination="48" id="67"/>
+                <outlet property="urlText" destination="10" id="32"/>
+                <outlet property="window" destination="1" id="3"/>
+            </connections>
+        </customObject>
+        <customObject id="-1" userLabel="First Responder" customClass="FirstResponder"/>
+        <customObject id="-3" userLabel="Application" customClass="NSObject"/>
+        <window title="Window" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" oneShot="NO" frameAutosaveName="Main Window" animationBehavior="default" id="1">
+            <windowStyleMask key="styleMask" titled="YES" closable="YES" miniaturizable="YES" resizable="YES" unifiedTitleAndToolbar="YES" fullSizeContentView="YES"/>
+            <windowPositionMask key="initialPositionMask" leftStrut="YES" rightStrut="YES" topStrut="YES" bottomStrut="YES"/>
+            <rect key="contentRect" x="517" y="330" width="776" height="608"/>
+            <rect key="screenRect" x="0.0" y="0.0" width="1920" height="1177"/>
+            <view key="contentView" id="2">
+                <rect key="frame" x="0.0" y="0.0" width="776" height="608"/>
+                <autoresizingMask key="autoresizingMask"/>
+                <subviews>
+                    <customView id="9">
+                        <rect key="frame" x="0.0" y="0.0" width="776" height="608"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                    </customView>
+                </subviews>
+            </view>
+            <toolbar key="toolbar" implicitIdentifier="994A0CB1-7575-4F39-A65B-7165AB1E8015" displayMode="iconOnly" sizeMode="regular" id="48">
+                <allowedToolbarItems>
+                    <toolbarItem implicitItemIdentifier="73DE9F4B-73E2-4036-A134-2D9E029DA980" label="Go Back" paletteLabel="Go Back" image="NSGoLeftTemplate" id="56" customClass="MBToolbarItem">
+                        <nil key="toolTip"/>
+                        <size key="minSize" width="32" height="27"/>
+                        <size key="maxSize" width="32" height="25"/>
+                        <button key="view" verticalHuggingPriority="750" id="40">
+                            <rect key="frame" x="10" y="14" width="32" height="25"/>
+                            <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+                            <buttonCell key="cell" type="roundTextured" bezelStyle="texturedRounded" image="NSGoLeftTemplate" imagePosition="overlaps" alignment="center" state="on" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="41">
+                                <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
+                                <font key="font" metaFont="system"/>
+                            </buttonCell>
+                        </button>
+                        <connections>
+                            <action selector="goBack:" target="-2" id="61"/>
+                        </connections>
+                    </toolbarItem>
+                    <toolbarItem implicitItemIdentifier="E1A9D32A-59E3-467B-9ABA-A95780416E69" label="Go Forward" paletteLabel="Go Forward" image="NSGoRightTemplate" id="57" customClass="MBToolbarItem">
+                        <nil key="toolTip"/>
+                        <size key="minSize" width="32" height="27"/>
+                        <size key="maxSize" width="32" height="27"/>
+                        <button key="view" verticalHuggingPriority="750" id="42">
+                            <rect key="frame" x="18" y="14" width="32" height="25"/>
+                            <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+                            <buttonCell key="cell" type="roundTextured" bezelStyle="texturedRounded" image="NSGoRightTemplate" imagePosition="overlaps" alignment="center" state="on" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="43">
+                                <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
+                                <font key="font" metaFont="system"/>
+                            </buttonCell>
+                        </button>
+                        <connections>
+                            <action selector="goForward:" target="-2" id="62"/>
+                        </connections>
+                    </toolbarItem>
+                    <toolbarItem implicitItemIdentifier="88C16109-D40F-4682-BCE4-CBEE2EDE32D2" label="Refresh" paletteLabel="Refresh" image="NSRefreshTemplate" id="58" customClass="MBToolbarItem">
+                        <nil key="toolTip"/>
+                        <size key="minSize" width="29" height="27"/>
+                        <size key="maxSize" width="29" height="27"/>
+                        <button key="view" verticalHuggingPriority="750" id="23">
+                            <rect key="frame" x="10" y="14" width="29" height="25"/>
+                            <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+                            <buttonCell key="cell" type="roundTextured" bezelStyle="texturedRounded" image="NSRefreshTemplate" imagePosition="overlaps" alignment="center" state="on" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="24">
+                                <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
+                                <font key="font" metaFont="system"/>
+                            </buttonCell>
+                            <connections>
+                                <action selector="reload:" target="-2" id="35"/>
+                            </connections>
+                        </button>
+                    </toolbarItem>
+                    <toolbarItem implicitItemIdentifier="F1738B7F-895C-48F7-955D-0915E150BE1B" label="Share" paletteLabel="Share" image="NSShareTemplate" id="dJx-dw-gcC" customClass="MBToolbarItem">
+                        <nil key="toolTip"/>
+                        <size key="minSize" width="29" height="27"/>
+                        <size key="maxSize" width="29" height="27"/>
+                        <button key="view" verticalHuggingPriority="750" id="1hB-AH-eUl">
+                            <rect key="frame" x="5" y="14" width="29" height="25"/>
+                            <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+                            <buttonCell key="cell" type="roundTextured" bezelStyle="texturedRounded" image="NSShareTemplate" imagePosition="overlaps" alignment="center" state="on" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="S1v-UD-QhI">
+                                <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
+                                <font key="font" metaFont="system"/>
+                                <connections>
+                                    <action selector="share:" target="-2" id="5e3-hg-bKN"/>
+                                </connections>
+                            </buttonCell>
+                        </button>
+                    </toolbarItem>
+                    <toolbarItem implicitItemIdentifier="255D29F2-C9AA-4B4B-BB43-B38FCD6A0BBB" label="Location" paletteLabel="Location" id="59">
+                        <nil key="toolTip"/>
+                        <size key="minSize" width="200" height="22"/>
+                        <size key="maxSize" width="100000" height="22"/>
+                        <textField key="view" verticalHuggingPriority="750" id="10">
+                            <rect key="frame" x="0.0" y="14" width="565" height="22"/>
+                            <autoresizingMask key="autoresizingMask" widthSizable="YES" flexibleMinY="YES"/>
+                            <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" selectable="YES" editable="YES" state="on" borderStyle="bezel" drawsBackground="YES" id="11">
+                                <font key="font" metaFont="system"/>
+                                <color key="textColor" name="textColor" catalog="System" colorSpace="catalog"/>
+                                <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
+                            </textFieldCell>
+                            <connections>
+                                <action selector="fetch:" target="-2" id="36"/>
+                            </connections>
+                        </textField>
+                    </toolbarItem>
+                    <toolbarItem implicitItemIdentifier="86912BAA-B8D0-400F-BFEE-71FC166986E6" label="Progress" paletteLabel="Progress" tag="-1" id="60">
+                        <nil key="toolTip"/>
+                        <size key="minSize" width="16" height="16"/>
+                        <size key="maxSize" width="16" height="16"/>
+                        <progressIndicator key="view" horizontalHuggingPriority="750" verticalHuggingPriority="750" maxValue="1" displayedWhenStopped="NO" bezeled="NO" controlSize="small" style="spinning" id="21">
+                            <rect key="frame" x="19" y="14" width="16" height="16"/>
+                            <autoresizingMask key="autoresizingMask" flexibleMinX="YES" flexibleMinY="YES"/>
+                        </progressIndicator>
+                    </toolbarItem>
+                </allowedToolbarItems>
+                <defaultToolbarItems>
+                    <toolbarItem reference="56"/>
+                    <toolbarItem reference="57"/>
+                    <toolbarItem reference="58"/>
+                    <toolbarItem reference="59"/>
+                    <toolbarItem reference="60"/>
+                    <toolbarItem reference="dJx-dw-gcC"/>
+                </defaultToolbarItems>
+            </toolbar>
+            <connections>
+                <outlet property="delegate" destination="-2" id="4"/>
+            </connections>
+        </window>
+    </objects>
+    <resources>
+        <image name="NSEnterFullScreenTemplate" width="15" height="15"/>
+        <image name="NSGoLeftTemplate" width="9" height="12"/>
+        <image name="NSGoRightTemplate" width="9" height="12"/>
+        <image name="NSRefreshTemplate" width="11" height="15"/>
+        <image name="NSShareTemplate" width="11" height="16"/>
+    </resources>
+</document>
diff --git a/Tools/Playwright/mac/BrowserWindowController.h b/Tools/Playwright/mac/BrowserWindowController.h
new file mode 100644
index 0000000000000000000000000000000000000000..4dbf13c8fb31a745ae8e1965a457d4fbcd8e5866
--- /dev/null
+++ b/Tools/Playwright/mac/BrowserWindowController.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+@class WKWebView;
+
+@interface BrowserWindowController : NSWindowController
+
+- (IBAction)goBack:(id)sender;
+- (IBAction)goForward:(id)sender;
+- (IBAction)reload:(id)sender;
+- (IBAction)saveAsPDF:(id)sender;
+- (IBAction)saveAsWebArchive:(id)sender;
+- (IBAction)zoomIn:(id)sender;
+- (IBAction)zoomOut:(id)sender;
+- (IBAction)resetZoom:(id)sender;
+- (IBAction)showHideWebInspector:(id)sender;
+
+- (IBAction)setPageScale:(id)sender;
+- (IBAction)setViewScale:(id)sender;
+- (instancetype)initWithConfiguration:(WKWebViewConfiguration *)configuration;
+- (void)loadURLString:(NSString *)urlString;
+- (WKWebView *)webView;
+
+@end
diff --git a/Tools/Playwright/mac/BrowserWindowController.m b/Tools/Playwright/mac/BrowserWindowController.m
new file mode 100644
index 0000000000000000000000000000000000000000..72edf5c432f58659765d16dabdb536b44942b1f2
--- /dev/null
+++ b/Tools/Playwright/mac/BrowserWindowController.m
@@ -0,0 +1,828 @@
+/*
+ * Copyright (C) 2010-2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "BrowserWindowController.h"
+
+#import "AppDelegate.h"
+#import <WebKit/WKFrameInfo.h>
+#import <WebKit/WKNavigationActionPrivate.h>
+#import <WebKit/WKNavigationDelegate.h>
+#import <WebKit/WKPreferencesPrivate.h>
+#import <WebKit/WKUIDelegate.h>
+#import <WebKit/WKUIDelegatePrivate.h>
+#import <WebKit/WKWebViewConfigurationPrivate.h>
+#import <WebKit/WKWebViewPrivate.h>
+#import <WebKit/WKWebViewPrivateForTesting.h>
+#import <WebKit/WKWebsiteDataStorePrivate.h>
+#import <WebKit/WebNSURLExtras.h>
+#import <WebKit/_WKIconLoadingDelegate.h>
+#import <WebKit/_WKInspector.h>
+#import <WebKit/_WKLinkIconParameters.h>
+#import <WebKit/_WKUserInitiatedAction.h>
+
+static void* keyValueObservingContext = &keyValueObservingContext;
+
+@interface PlaywrightNSTextFinder : NSTextFinder
+
+@property (nonatomic, copy) dispatch_block_t hideInterfaceCallback;
+
+@end
+
+@implementation PlaywrightNSTextFinder
+
+- (void)performAction:(NSTextFinderAction)op
+{
+    [super performAction:op];
+
+    if (op == NSTextFinderActionHideFindInterface && _hideInterfaceCallback)
+        _hideInterfaceCallback();
+}
+
+@end
+
+@interface BrowserWindowController () <NSTextFinderBarContainer, WKNavigationDelegate, WKUIDelegate, _WKIconLoadingDelegate, NSSharingServicePickerDelegate, NSSharingServiceDelegate>
+@end
+
+@implementation BrowserWindowController {
+    IBOutlet NSProgressIndicator *progressIndicator;
+    IBOutlet NSButton *reloadButton;
+    IBOutlet NSButton *backButton;
+    IBOutlet NSButton *forwardButton;
+    IBOutlet NSButton *share;
+    IBOutlet NSToolbar *toolbar;
+    IBOutlet NSTextField *urlText;
+    IBOutlet NSView *containerView;
+    IBOutlet NSButton *toggleUseShrinkToFitButton;
+
+    WKWebViewConfiguration *_configuration;
+    WKWebView *_webView;
+    BOOL _zoomTextOnly;
+    BOOL _isPrivateBrowsingWindow;
+    NSAlert* _alert;
+
+    BOOL _useShrinkToFit;
+
+    PlaywrightNSTextFinder *_textFinder;
+    NSView *_textFindBarView;
+    BOOL _findBarVisible;
+}
+
+- (id)initWithWindow:(NSWindow *)window
+{
+    self = [super initWithWindow:window];
+    return self;
+}
+
+- (void)windowDidLoad
+{
+    [share sendActionOn:NSEventMaskLeftMouseDown];
+    [super windowDidLoad];
+}
+
+- (IBAction)openLocation:(id)sender
+{
+    [[self window] makeFirstResponder:urlText];
+}
+
+- (NSString *)addProtocolIfNecessary:(NSString *)address
+{
+    if ([address rangeOfString:@"://"].length > 0)
+        return address;
+
+    if ([address hasPrefix:@"data:"])
+        return address;
+
+    if ([address hasPrefix:@"about:"])
+        return address;
+
+    return [@"http://" stringByAppendingString:address];
+}
+
+- (IBAction)share:(id)sender
+{
+    NSSharingServicePicker *picker = [[NSSharingServicePicker alloc] initWithItems:@[ self.currentURL ]];
+    picker.delegate = self;
+    [picker showRelativeToRect:NSZeroRect ofView:sender preferredEdge:NSRectEdgeMinY];
+}
+
+- (IBAction)showHideWebView:(id)sender
+{
+    self.mainContentView.hidden = !self.mainContentView.isHidden;
+}
+
+- (CGFloat)pageScaleForMenuItemTag:(NSInteger)tag
+{
+    if (tag == 1)
+        return 1;
+    if (tag == 2)
+        return 1.25;
+    if (tag == 3)
+        return 1.5;
+    if (tag == 4)
+        return 2.0;
+
+    return 1;
+}
+
+- (void)awakeFromNib
+{
+    _webView = [[WKWebView alloc] initWithFrame:[containerView bounds] configuration:_configuration];
+    _webView._windowOcclusionDetectionEnabled = NO;
+
+    _webView.allowsMagnification = YES;
+    _webView.allowsBackForwardNavigationGestures = YES;
+
+    [_webView setAutoresizingMask:(NSViewWidthSizable | NSViewHeightSizable)];
+    [containerView addSubview:_webView];
+
+    [progressIndicator bind:NSHiddenBinding toObject:_webView withKeyPath:@"loading" options:@{ NSValueTransformerNameBindingOption : NSNegateBooleanTransformerName }];
+    [progressIndicator bind:NSValueBinding toObject:_webView withKeyPath:@"estimatedProgress" options:nil];
+
+    [_webView addObserver:self forKeyPath:@"title" options:0 context:keyValueObservingContext];
+    [_webView addObserver:self forKeyPath:@"URL" options:0 context:keyValueObservingContext];
+
+    _webView.navigationDelegate = self;
+    _webView.UIDelegate = self;
+
+    _webView._observedRenderingProgressEvents = _WKRenderingProgressEventFirstLayout
+        | _WKRenderingProgressEventFirstVisuallyNonEmptyLayout
+        | _WKRenderingProgressEventFirstPaintWithSignificantArea
+        | _WKRenderingProgressEventFirstLayoutAfterSuppressedIncrementalRendering
+        | _WKRenderingProgressEventFirstPaintAfterSuppressedIncrementalRendering;
+
+    _webView.customUserAgent = @"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_2) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.4 Safari/605.1.15";
+
+    _webView._usePlatformFindUI = NO;
+
+    _textFinder = [[PlaywrightNSTextFinder alloc] init];
+    _textFinder.incrementalSearchingEnabled = YES;
+    _textFinder.incrementalSearchingShouldDimContentView = NO;
+    _textFinder.client = _webView;
+    _textFinder.findBarContainer = self;
+    _textFinder.hideInterfaceCallback = ^{
+        [_webView _hideFindUI];
+    };
+
+    _zoomTextOnly = NO;
+}
+
+- (instancetype)initWithConfiguration:(WKWebViewConfiguration *)configuration
+{
+    if (!(self = [super initWithWindowNibName:@"BrowserWindow"]))
+        return nil;
+    _configuration = [configuration copy];
+    _isPrivateBrowsingWindow = !_configuration.websiteDataStore.isPersistent;
+    self.window.styleMask &= ~NSWindowStyleMaskFullSizeContentView;
+    return self;
+}
+
+- (void)dealloc
+{
+    [[NSNotificationCenter defaultCenter] removeObserver:self];
+
+    [progressIndicator unbind:NSHiddenBinding];
+    [progressIndicator unbind:NSValueBinding];
+
+    [_textFinder release];
+    [_webView release];
+    [_configuration release];
+
+    [super dealloc];
+}
+
+- (IBAction)fetch:(id)sender
+{
+    [urlText setStringValue:[self addProtocolIfNecessary:urlText.stringValue]];
+    NSURL *url = [NSURL _webkit_URLWithUserTypedString:urlText.stringValue];
+    [_webView loadRequest:[NSURLRequest requestWithURL:url]];
+}
+
+- (IBAction)setPageScale:(id)sender
+{
+    CGFloat scale = [self pageScaleForMenuItemTag:[sender tag]];
+    [_webView _setPageScale:scale withOrigin:CGPointZero];
+}
+
+- (CGFloat)viewScaleForMenuItemTag:(NSInteger)tag
+{
+    if (tag == 1)
+        return 1;
+    if (tag == 2)
+        return 0.75;
+    if (tag == 3)
+        return 0.5;
+    if (tag == 4)
+        return 0.25;
+
+    return 1;
+}
+
+- (IBAction)setViewScale:(id)sender
+{
+    CGFloat scale = [self viewScaleForMenuItemTag:[sender tag]];
+    CGFloat oldScale = [_webView _viewScale];
+
+    if (scale == oldScale)
+        return;
+
+    [_webView _setLayoutMode:_WKLayoutModeDynamicSizeComputedFromViewScale];
+
+    NSRect oldFrame = self.window.frame;
+    NSSize newFrameSize = NSMakeSize(oldFrame.size.width * (scale / oldScale), oldFrame.size.height * (scale / oldScale));
+    [self.window setFrame:NSMakeRect(oldFrame.origin.x, oldFrame.origin.y - (newFrameSize.height - oldFrame.size.height), newFrameSize.width, newFrameSize.height) display:NO animate:NO];
+
+    [_webView _setViewScale:scale];
+}
+
+static BOOL areEssentiallyEqual(double a, double b)
+{
+    double tolerance = 0.001;
+    return (fabs(a - b) <= tolerance);
+}
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-implementations"
+- (BOOL)validateMenuItem:(NSMenuItem *)menuItem
+#pragma GCC diagnostic pop
+{
+    SEL action = menuItem.action;
+
+    if (action == @selector(saveAsPDF:))
+        return YES;
+    if (action == @selector(saveAsWebArchive:))
+        return YES;
+
+    if (action == @selector(zoomIn:))
+        return [self canZoomIn];
+    if (action == @selector(zoomOut:))
+        return [self canZoomOut];
+    if (action == @selector(resetZoom:))
+        return [self canResetZoom];
+
+    if (action == @selector(toggleZoomMode:))
+        [menuItem setState:_zoomTextOnly ? NSControlStateValueOn : NSControlStateValueOff];
+    else if (action == @selector(showHideWebInspector:))
+        [menuItem setTitle:_webView._inspector.isVisible ? @"Close Web Inspector" : @"Show Web Inspector"];
+
+    if (action == @selector(setPageScale:))
+        [menuItem setState:areEssentiallyEqual([_webView _pageScale], [self pageScaleForMenuItemTag:[menuItem tag]])];
+
+    if (action == @selector(setViewScale:))
+        [menuItem setState:areEssentiallyEqual([_webView _viewScale], [self viewScaleForMenuItemTag:[menuItem tag]])];
+
+    return YES;
+}
+
+- (IBAction)reload:(id)sender
+{
+    [_webView reload];
+}
+
+- (IBAction)goBack:(id)sender
+{
+    [_webView goBack];
+}
+
+- (IBAction)goForward:(id)sender
+{
+    [_webView goForward];
+}
+
+- (IBAction)toggleZoomMode:(id)sender
+{
+    if (_zoomTextOnly) {
+        _zoomTextOnly = NO;
+        double currentTextZoom = _webView._textZoomFactor;
+        _webView._textZoomFactor = 1;
+        _webView.pageZoom = currentTextZoom;
+    } else {
+        _zoomTextOnly = YES;
+        double currentPageZoom = _webView._pageZoomFactor;
+        _webView._textZoomFactor = currentPageZoom;
+        _webView.pageZoom = 1;
+    }
+}
+
+- (IBAction)resetZoom:(id)sender
+{
+    if (![self canResetZoom])
+        return;
+
+    if (_zoomTextOnly)
+        _webView._textZoomFactor = 1;
+    else
+        _webView.pageZoom = 1;
+}
+
+- (BOOL)canResetZoom
+{
+    return _zoomTextOnly ? (_webView._textZoomFactor != 1) : (_webView.pageZoom != 1);
+}
+
+- (IBAction)showHideWebInspector:(id)sender
+{
+    _WKInspector *inspector = _webView._inspector;
+    if (inspector.isVisible)
+        [inspector hide];
+    else
+        [inspector show];
+}
+
+- (NSURL *)currentURL
+{
+    return _webView.URL;
+}
+
+- (NSView *)mainContentView
+{
+    return _webView;
+}
+
+- (BOOL)validateUserInterfaceItem:(id <NSValidatedUserInterfaceItem>)item
+{
+    SEL action = item.action;
+
+    if (action == @selector(goBack:) || action == @selector(goForward:))
+        return [_webView validateUserInterfaceItem:item];
+
+    return YES;
+}
+
+- (void)validateToolbar
+{
+    [toolbar validateVisibleItems];
+}
+
+- (BOOL)windowShouldClose:(id)sender
+{
+    return YES;
+}
+
+- (void)windowWillClose:(NSNotification *)notification
+{
+    [[[NSApplication sharedApplication] browserAppDelegate] browserWindowWillClose:self.window];
+    [_webView removeObserver:self forKeyPath:@"title"];
+    [_webView removeObserver:self forKeyPath:@"URL"];
+    [self autorelease];
+}
+
+- (void)webViewDidClose:(WKWebView *)webView {
+    [self.window close];
+}
+
+#define DefaultMinimumZoomFactor (.5)
+#define DefaultMaximumZoomFactor (3.0)
+#define DefaultZoomFactorRatio (1.2)
+
+- (CGFloat)currentZoomFactor
+{
+    return _zoomTextOnly ? _webView._textZoomFactor : _webView.pageZoom;
+}
+
+- (void)setCurrentZoomFactor:(CGFloat)factor
+{
+    if (_zoomTextOnly)
+        _webView._textZoomFactor = factor;
+    else
+        _webView.pageZoom = factor;
+}
+
+- (BOOL)canZoomIn
+{
+    return self.currentZoomFactor * DefaultZoomFactorRatio < DefaultMaximumZoomFactor;
+}
+
+- (void)zoomIn:(id)sender
+{
+    if (!self.canZoomIn)
+        return;
+
+    self.currentZoomFactor *= DefaultZoomFactorRatio;
+}
+
+- (BOOL)canZoomOut
+{
+    return self.currentZoomFactor / DefaultZoomFactorRatio > DefaultMinimumZoomFactor;
+}
+
+- (void)zoomOut:(id)sender
+{
+    if (!self.canZoomIn)
+        return;
+
+    self.currentZoomFactor /= DefaultZoomFactorRatio;
+}
+
+- (void)updateTitle:(NSString *)title
+{
+    if (!title) {
+        NSURL *url = _webView.URL;
+        title = url.lastPathComponent ?: url._web_userVisibleString;
+    }
+
+    self.window.title = [NSString stringWithFormat:@"%@%@ [%d]%@", _isPrivateBrowsingWindow ? @"🙈 " : @"", title, _webView._webProcessIdentifier, @""];
+}
+
+- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
+{
+    if (context != keyValueObservingContext || object != _webView)
+        return;
+
+    if ([keyPath isEqualToString:@"title"])
+        [self updateTitle:_webView.title];
+    else if ([keyPath isEqualToString:@"URL"])
+        [self updateTextFieldFromURL:_webView.URL];
+}
+
+- (nullable WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWebViewConfiguration *)configuration forNavigationAction:(WKNavigationAction *)navigationAction windowFeatures:(WKWindowFeatures *)windowFeatures
+{
+    BrowserWindowController *controller = [[BrowserWindowController alloc] initWithConfiguration:configuration];
+    [controller.window makeKeyAndOrderFront:self];
+
+    return controller->_webView;
+}
+
+- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler
+{
+    NSAlert* alert = [[NSAlert alloc] init];
+
+    [alert setMessageText:[NSString stringWithFormat:@"JavaScript alert dialog from %@.", [frame.request.URL absoluteString]]];
+    [alert setInformativeText:message];
+    [alert addButtonWithTitle:@"OK"];
+
+    _alert = alert;
+    [alert beginSheetModalForWindow:self.window completionHandler:^void (NSModalResponse response) {
+        completionHandler();
+        [alert release];
+        _alert = nil;
+    }];
+}
+
+- (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL result))completionHandler
+{
+    NSAlert* alert = [[NSAlert alloc] init];
+
+    [alert setMessageText:[NSString stringWithFormat:@"JavaScript confirm dialog from %@.", [frame.request.URL  absoluteString]]];
+    [alert setInformativeText:message];
+
+    [alert addButtonWithTitle:@"OK"];
+    [alert addButtonWithTitle:@"Cancel"];
+
+    _alert = alert;
+    [alert beginSheetModalForWindow:self.window completionHandler:^void (NSModalResponse response) {
+        completionHandler(response == NSAlertFirstButtonReturn);
+        [alert release];
+        _alert = nil;
+    }];
+}
+
+- (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString *result))completionHandler
+{
+    NSAlert* alert = [[NSAlert alloc] init];
+
+    [alert setMessageText:[NSString stringWithFormat:@"JavaScript prompt dialog from %@.", [frame.request.URL absoluteString]]];
+    [alert setInformativeText:prompt];
+
+    [alert addButtonWithTitle:@"OK"];
+    [alert addButtonWithTitle:@"Cancel"];
+
+    NSTextField* input = [[NSTextField alloc] initWithFrame:NSMakeRect(0, 0, 200, 24)];
+    [input setStringValue:defaultText];
+    [alert setAccessoryView:input];
+
+    _alert = alert;
+    [alert beginSheetModalForWindow:self.window completionHandler:^void (NSModalResponse response) {
+        [input validateEditing];
+        completionHandler(response == NSAlertFirstButtonReturn ? [input stringValue] : nil);
+        [alert release];
+        _alert = nil;
+    }];
+}
+
+- (void)webView:(WKWebView *)webView handleJavaScriptDialog:(BOOL)accept value:(NSString *)value
+{
+    if (!_alert)
+        return;
+    NSTextField* input = (NSTextField*)_alert.accessoryView;
+    if (accept && input && value)
+        [input setStringValue:value];
+    [self.window endSheet:_alert.window returnCode: accept ? NSAlertFirstButtonReturn : NSModalResponseCancel];
+}
+
+#if __has_feature(objc_generics)
+- (void)webView:(WKWebView *)webView runOpenPanelWithParameters:(WKOpenPanelParameters *)parameters initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSArray<NSURL *> * URLs))completionHandler
+#else
+- (void)webView:(WKWebView *)webView runOpenPanelWithParameters:(WKOpenPanelParameters *)parameters initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSArray *URLs))completionHandler
+#endif
+{
+    NSOpenPanel *openPanel = [NSOpenPanel openPanel];
+
+    openPanel.allowsMultipleSelection = parameters.allowsMultipleSelection;
+
+    [openPanel beginSheetModalForWindow:webView.window completionHandler:^(NSInteger result) {
+        if (result == NSModalResponseOK)
+            completionHandler(openPanel.URLs);
+        else
+            completionHandler(nil);
+    }];
+}
+
+- (void)_webView:(WebView *)sender runBeforeUnloadConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL result))completionHandler
+{
+    NSAlert *alert = [[NSAlert alloc] init];
+
+    alert.messageText = [NSString stringWithFormat:@"JavaScript before unload dialog from %@.", [frame.request.URL absoluteString]];
+    alert.informativeText = message;
+
+    [alert addButtonWithTitle:@"Leave Page"];
+    [alert addButtonWithTitle:@"Stay On Page"];
+
+    _alert = alert;
+    [alert beginSheetModalForWindow:self.window completionHandler:^void (NSModalResponse response) {
+        completionHandler(response == NSAlertFirstButtonReturn);
+        [alert release];
+        _alert = nil;
+    }];
+}
+
+- (WKDragDestinationAction)_webView:(WKWebView *)webView dragDestinationActionMaskForDraggingInfo:(id)draggingInfo
+{
+    return WKDragDestinationActionAny;
+}
+
+- (void)updateTextFieldFromURL:(NSURL *)URL
+{
+    if (!URL)
+        return;
+
+    if (!URL.absoluteString.length)
+        return;
+
+    urlText.stringValue = [URL _web_userVisibleString];
+}
+
+- (void)loadURLString:(NSString *)urlString
+{
+    // FIXME: We shouldn't have to set the url text here.
+    [urlText setStringValue:urlString];
+    [self fetch:nil];
+}
+
+- (void)loadHTMLString:(NSString *)HTMLString
+{
+    [_webView loadHTMLString:HTMLString baseURL:nil];
+}
+
+static NSSet *dataTypes()
+{
+    return [WKWebsiteDataStore allWebsiteDataTypes];
+}
+
+- (IBAction)fetchWebsiteData:(id)sender
+{
+    [_configuration.websiteDataStore _fetchDataRecordsOfTypes:dataTypes() withOptions:_WKWebsiteDataStoreFetchOptionComputeSizes completionHandler:^(NSArray *websiteDataRecords) {
+        NSLog(@"did fetch website data %@.", websiteDataRecords);
+    }];
+}
+
+- (IBAction)fetchAndClearWebsiteData:(id)sender
+{
+    [_configuration.websiteDataStore fetchDataRecordsOfTypes:dataTypes() completionHandler:^(NSArray *websiteDataRecords) {
+        [_configuration.websiteDataStore removeDataOfTypes:dataTypes() forDataRecords:websiteDataRecords completionHandler:^{
+            [_configuration.websiteDataStore fetchDataRecordsOfTypes:dataTypes() completionHandler:^(NSArray *websiteDataRecords) {
+                NSLog(@"did clear website data, after clearing data is %@.", websiteDataRecords);
+            }];
+        }];
+    }];
+}
+
+- (IBAction)clearWebsiteData:(id)sender
+{
+    [_configuration.websiteDataStore removeDataOfTypes:dataTypes() modifiedSince:[NSDate distantPast] completionHandler:^{
+        NSLog(@"Did clear website data.");
+    }];
+}
+
+- (IBAction)printWebView:(id)sender
+{
+    [[_webView printOperationWithPrintInfo:[NSPrintInfo sharedPrintInfo]] runOperationModalForWindow:self.window delegate:nil didRunSelector:nil contextInfo:nil];
+}
+
+#pragma mark WKNavigationDelegate
+
+- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler
+{
+    LOG(@"decidePolicyForNavigationAction");
+
+    if (navigationAction._canHandleRequest) {
+        decisionHandler(WKNavigationActionPolicyAllow);
+        return;
+    }
+    decisionHandler(WKNavigationActionPolicyCancel);
+}
+
+- (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler
+{
+    LOG(@"decidePolicyForNavigationResponse");
+    decisionHandler(WKNavigationResponsePolicyAllow);
+}
+
+- (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation
+{
+    LOG(@"didStartProvisionalNavigation: %@", navigation);
+}
+
+- (void)webView:(WKWebView *)webView didReceiveServerRedirectForProvisionalNavigation:(WKNavigation *)navigation
+{
+    LOG(@"didReceiveServerRedirectForProvisionalNavigation: %@", navigation);
+}
+
+- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation withError:(NSError *)error
+{
+    LOG(@"didFailProvisionalNavigation: %@navigation, error: %@", navigation, error);
+}
+
+- (void)webView:(WKWebView *)webView didCommitNavigation:(WKNavigation *)navigation
+{
+    LOG(@"didCommitNavigation: %@", navigation);
+    [self updateTitle:nil];
+}
+
+- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation
+{
+    LOG(@"didFinishNavigation: %@", navigation);
+}
+
+- (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential *__nullable credential))completionHandler
+{
+    LOG(@"didReceiveAuthenticationChallenge: %@", challenge);
+    if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodHTTPBasic]) {
+        NSAlert *alert = [[NSAlert alloc] init];
+        NSView *container = [[[NSView alloc] initWithFrame:NSMakeRect(0, 0, 200, 48)] autorelease];
+        NSTextField *userInput = [[[NSTextField alloc] initWithFrame:NSMakeRect(0, 24, 200, 24)] autorelease];
+        NSTextField *passwordInput = [[[NSSecureTextField alloc] initWithFrame:NSMakeRect(0, 0, 200, 24)] autorelease];
+
+        [alert setMessageText:[NSString stringWithFormat:@"Log in to %@:%lu.", challenge.protectionSpace.host, challenge.protectionSpace.port]];
+        [alert addButtonWithTitle:@"Log in"];
+        [alert addButtonWithTitle:@"Cancel"];
+        [container addSubview:userInput];
+        [container addSubview:passwordInput];
+        [alert setAccessoryView:container];
+        [userInput setNextKeyView:passwordInput];
+        [alert.window setInitialFirstResponder:userInput];
+
+        [alert beginSheetModalForWindow:self.window completionHandler:^(NSModalResponse response) {
+            [userInput validateEditing];
+            if (response == NSAlertFirstButtonReturn)
+                completionHandler(NSURLSessionAuthChallengeUseCredential, [[[NSURLCredential alloc] initWithUser:[userInput stringValue] password:[passwordInput stringValue] persistence:NSURLCredentialPersistenceForSession] autorelease]);
+            else
+                completionHandler(NSURLSessionAuthChallengeRejectProtectionSpace, nil);
+            [alert release];
+        }];
+        return;
+    }
+    completionHandler(NSURLSessionAuthChallengeRejectProtectionSpace, nil);
+}
+
+- (void)webView:(WKWebView *)webView didFailNavigation:(WKNavigation *)navigation withError:(NSError *)error
+{
+    LOG(@"didFailNavigation: %@, error %@", navigation, error);
+}
+
+- (void)webViewWebContentProcessDidTerminate:(WKWebView *)webView
+{
+    NSLog(@"WebContent process crashed; reloading");
+    [self reload:nil];
+}
+
+- (void)_webView:(WKWebView *)webView renderingProgressDidChange:(_WKRenderingProgressEvents)progressEvents
+{
+    if (progressEvents & _WKRenderingProgressEventFirstLayout)
+        LOG(@"renderingProgressDidChange: %@", @"first layout");
+
+    if (progressEvents & _WKRenderingProgressEventFirstVisuallyNonEmptyLayout)
+        LOG(@"renderingProgressDidChange: %@", @"first visually non-empty layout");
+
+    if (progressEvents & _WKRenderingProgressEventFirstPaintWithSignificantArea)
+        LOG(@"renderingProgressDidChange: %@", @"first paint with significant area");
+
+    if (progressEvents & _WKRenderingProgressEventFirstLayoutAfterSuppressedIncrementalRendering)
+        LOG(@"renderingProgressDidChange: %@", @"first layout after suppressed incremental rendering");
+
+    if (progressEvents & _WKRenderingProgressEventFirstPaintAfterSuppressedIncrementalRendering)
+        LOG(@"renderingProgressDidChange: %@", @"first paint after suppressed incremental rendering");
+}
+
+- (void)webView:(WKWebView *)webView shouldLoadIconWithParameters:(_WKLinkIconParameters *)parameters completionHandler:(void (^)(void (^)(NSData*)))completionHandler
+{
+    completionHandler(^void (NSData *data) {
+        LOG(@"Icon URL %@ received icon data of length %u", parameters.url, (unsigned)data.length);
+    });
+}
+
+#pragma mark Find in Page
+
+- (IBAction)performTextFinderAction:(id)sender
+{
+    [_textFinder performAction:[sender tag]];
+}
+
+- (NSView *)findBarView
+{
+    return _textFindBarView;
+}
+
+- (void)setFindBarView:(NSView *)findBarView
+{
+    _textFindBarView = findBarView;
+    _findBarVisible = YES;
+    [_textFindBarView setFrame:NSMakeRect(0, 0, containerView.bounds.size.width, _textFindBarView.frame.size.height)];
+}
+
+- (BOOL)isFindBarVisible
+{
+    return _findBarVisible;
+}
+
+- (void)setFindBarVisible:(BOOL)findBarVisible
+{
+    _findBarVisible = findBarVisible;
+    if (findBarVisible)
+        [containerView addSubview:_textFindBarView];
+    else
+        [_textFindBarView removeFromSuperview];
+}
+
+- (NSView *)contentView
+{
+    return _webView;
+}
+
+- (void)findBarViewDidChangeHeight
+{
+}
+
+- (void)_webView:(WKWebView *)webView requestMediaCaptureAuthorization: (_WKCaptureDevices)devices decisionHandler:(void (^)(BOOL authorized))decisionHandler
+{
+    decisionHandler(true);
+}
+
+- (void)_webView:(WKWebView *)webView includeSensitiveMediaDeviceDetails:(void (^)(BOOL includeSensitiveDetails))decisionHandler
+{
+    decisionHandler(false);
+}
+
+- (IBAction)saveAsPDF:(id)sender
+{
+    NSSavePanel *panel = [NSSavePanel savePanel];
+    panel.allowedFileTypes = @[ @"pdf" ];
+    [panel beginSheetModalForWindow:self.window completionHandler:^(NSInteger result) {
+        if (result == NSModalResponseOK) {
+            [_webView createPDFWithConfiguration:nil completionHandler:^(NSData *pdfSnapshotData, NSError *error) {
+                [pdfSnapshotData writeToURL:[panel URL] options:0 error:nil];
+            }];
+        }
+    }];
+}
+
+- (IBAction)saveAsWebArchive:(id)sender
+{
+    NSSavePanel *panel = [NSSavePanel savePanel];
+    panel.allowedFileTypes = @[ @"webarchive" ];
+    [panel beginSheetModalForWindow:self.window completionHandler:^(NSInteger result) {
+        if (result == NSModalResponseOK) {
+            [_webView createWebArchiveDataWithCompletionHandler:^(NSData *archiveData, NSError *error) {
+                [archiveData writeToURL:[panel URL] options:0 error:nil];
+            }];
+        }
+    }];
+}
+
+- (WKWebView *)webView
+{
+    return _webView;
+}
+
+@end
diff --git a/Tools/Playwright/mac/CMakeLists.txt b/Tools/Playwright/mac/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..410d47425b79367114b17274355350894a70a5e6
--- /dev/null
+++ b/Tools/Playwright/mac/CMakeLists.txt
@@ -0,0 +1,43 @@
+set(PLAYWRIGHT_DIR "${TOOLS_DIR}/Playwright/mac")
+
+#FIXME: This should not need WEBCORE_EXPORT defined.  This means we are including WebCore headers, and we should not.
+add_definitions("-include Playwright_Prefix.pch -DWEBCORE_EXPORT=")
+
+set(Playwright_SOURCES
+    ${PLAYWRIGHT_DIR}/AppDelegate.m
+    ${PLAYWRIGHT_DIR}/BrowserWindowController.m
+    ${PLAYWRIGHT_DIR}/main.m
+    ${TOOLS_DIR}/Playwright/MBToolbarItem.m
+)
+
+set(Playwright_INCLUDE_DIRECTORIES
+    ${CMAKE_SOURCE_DIR}/Source
+    ${FORWARDING_HEADERS_DIR}
+    ${PLAYWRIGHT_DIR}
+)
+
+set(Playwright_LIBRARIES
+    WebKit
+)
+
+set(CMAKE_EXE_LINKER_FLAGS "-framework Cocoa")
+
+set(EXECUTABLE_NAME Playwright)
+set(PRODUCT_NAME Playwright)
+
+set(Playwright_Contents_Directory ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/Playwright.app/Contents)
+make_directory(${Playwright_Contents_Directory}/Resources)
+add_custom_command(OUTPUT ${Playwright_Contents_Directory}/Resources/BrowserWindow.nib
+    COMMAND ibtool --compile ${Playwright_Contents_Directory}/Resources/BrowserWindow.nib ${PLAYWRIGHT_DIR}/BrowserWindow.xib VERBATIM)
+add_custom_command(OUTPUT ${Playwright_Contents_Directory}/Resources/MainMenu.nib
+    COMMAND ibtool --compile ${Playwright_Contents_Directory}/Resources/MainMenu.nib ${PLAYWRIGHT_DIR}/MainMenu.xib VERBATIM)
+add_custom_target(PlaywrightNibs ALL DEPENDS
+    ${Playwright_Contents_Directory}/Resources/BrowserWindow.nib
+    ${Playwright_Contents_Directory}/Resources/MainMenu.nib
+)
+
+include_directories(${Playwright_INCLUDE_DIRECTORIES})
+add_executable(Playwright MACOSX_BUNDLE ${Playwright_SOURCES})
+set_target_properties(Playwright PROPERTIES MACOSX_BUNDLE_INFO_PLIST ${PLAYWRIGHT_DIR}/Info.plist)
+target_link_libraries(Playwright ${Playwright_LIBRARIES})
+add_dependencies(Playwright PlaywrightNibs)
diff --git a/Tools/Playwright/mac/Info.plist b/Tools/Playwright/mac/Info.plist
new file mode 100644
index 0000000000000000000000000000000000000000..4ed50c40f2f0dfd0ddf7c546b3451ab426c0501e
--- /dev/null
+++ b/Tools/Playwright/mac/Info.plist
@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>English</string>
+	<key>CFBundleExecutable</key>
+	<string>${EXECUTABLE_NAME}</string>
+	<key>CFBundleIconFile</key>
+	<string>WebKit Browser</string>
+	<key>CFBundleIdentifier</key>
+	<string>${PRODUCT_BUNDLE_IDENTIFIER}</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>${PRODUCT_NAME}</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>LSMinimumSystemVersion</key>
+	<string>${MACOSX_DEPLOYMENT_TARGET}</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>NSMainNibFile</key>
+	<string>MainMenu</string>
+	<key>NSPrincipalClass</key>
+	<string>NSApplication</string>
+	<key>NSAppTransportSecurity</key>
+	<dict>
+		<key>NSAllowsArbitraryLoads</key>
+		<true/>
+	</dict>
+	<key>NSSupportsAutomaticGraphicsSwitching</key>
+	<true/>
+	<key>CFBundleDocumentTypes</key>
+	<array>
+		<dict>
+			<key>CFBundleTypeExtensions</key>
+			<array>
+				<string>html</string>
+			</array>
+			<key>CFBundleTypeMIMETypes</key>
+			<array>
+				<string>text/html</string>
+			</array>
+			<key>CFBundleTypeName</key>
+			<string>HTML</string>
+			<key>CFBundleTypeRole</key>
+			<string>Editor</string>
+		</dict>
+	</array>
+</dict>
+</plist>
diff --git a/Tools/Playwright/mac/MainMenu.xib b/Tools/Playwright/mac/MainMenu.xib
new file mode 100644
index 0000000000000000000000000000000000000000..b16d639a1ad18354e058c613987d846acd70b361
--- /dev/null
+++ b/Tools/Playwright/mac/MainMenu.xib
@@ -0,0 +1,333 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="15505" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES">
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="15505"/>
+    </dependencies>
+    <objects>
+        <customObject id="-2" userLabel="File's Owner" customClass="NSApplication">
+            <connections>
+                <outlet property="delegate" destination="494" id="495"/>
+            </connections>
+        </customObject>
+        <customObject id="-1" userLabel="First Responder" customClass="FirstResponder"/>
+        <customObject id="-3" userLabel="Application" customClass="NSObject"/>
+        <menu title="AMainMenu" systemMenu="main" id="29">
+            <items>
+                <menuItem title="Playwright" id="56">
+                    <menu key="submenu" title="Playwright" systemMenu="apple" id="57">
+                        <items>
+                            <menuItem title="About Playwright" id="58">
+                                <modifierMask key="keyEquivalentModifierMask"/>
+                                <connections>
+                                    <action selector="orderFrontStandardAboutPanel:" target="-2" id="142"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem isSeparatorItem="YES" id="236">
+                                <modifierMask key="keyEquivalentModifierMask" command="YES"/>
+                            </menuItem>
+                            <menuItem title="Preferences…" keyEquivalent="," id="129"/>
+                            <menuItem isSeparatorItem="YES" id="143">
+                                <modifierMask key="keyEquivalentModifierMask" command="YES"/>
+                            </menuItem>
+                            <menuItem title="Services" id="131">
+                                <menu key="submenu" title="Services" systemMenu="services" id="130"/>
+                            </menuItem>
+                            <menuItem isSeparatorItem="YES" id="144">
+                                <modifierMask key="keyEquivalentModifierMask" command="YES"/>
+                            </menuItem>
+                            <menuItem title="Hide Playwright" keyEquivalent="h" id="134">
+                                <connections>
+                                    <action selector="hide:" target="-1" id="367"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Hide Others" keyEquivalent="h" id="145">
+                                <modifierMask key="keyEquivalentModifierMask" option="YES" command="YES"/>
+                                <connections>
+                                    <action selector="hideOtherApplications:" target="-1" id="368"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Show All" id="150">
+                                <connections>
+                                    <action selector="unhideAllApplications:" target="-1" id="370"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem isSeparatorItem="YES" id="149">
+                                <modifierMask key="keyEquivalentModifierMask" command="YES"/>
+                            </menuItem>
+                            <menuItem title="Quit Playwright" keyEquivalent="q" id="136">
+                                <connections>
+                                    <action selector="terminate:" target="-3" id="449"/>
+                                </connections>
+                            </menuItem>
+                        </items>
+                    </menu>
+                </menuItem>
+                <menuItem title="File" id="83">
+                    <menu key="submenu" title="File" id="81">
+                        <items>
+                            <menuItem title="Open Location " tag="1" keyEquivalent="l" id="82">
+                                <connections>
+                                    <action selector="openLocation:" target="-1" id="575"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem isSeparatorItem="YES" id="79">
+                                <modifierMask key="keyEquivalentModifierMask" command="YES"/>
+                            </menuItem>
+                            <menuItem title="Close" keyEquivalent="w" id="73">
+                                <connections>
+                                    <action selector="performClose:" target="-1" id="193"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Save" keyEquivalent="s" id="75">
+                                <connections>
+                                    <action selector="saveDocument:" target="-1" id="362"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Save As…" keyEquivalent="S" id="80">
+                                <modifierMask key="keyEquivalentModifierMask" shift="YES" command="YES"/>
+                                <connections>
+                                    <action selector="saveDocumentAs:" target="-1" id="363"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Save As PDF…" keyEquivalent="S" id="gmS-3Q-oLs">
+                                <modifierMask key="keyEquivalentModifierMask" option="YES" command="YES"/>
+                                <connections>
+                                    <action selector="saveAsPDF:" target="-1" id="25T-Id-334"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Save As WebArchive..." id="112">
+                                <modifierMask key="keyEquivalentModifierMask"/>
+                                <connections>
+                                    <action selector="saveAsWebArchive:" target="-1" id="AGx-3e-6Nt"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem isSeparatorItem="YES" id="74">
+                                <modifierMask key="keyEquivalentModifierMask" command="YES"/>
+                            </menuItem>
+                            <menuItem title="Page Setup..." keyEquivalent="P" id="77">
+                                <modifierMask key="keyEquivalentModifierMask" shift="YES" command="YES"/>
+                                <connections>
+                                    <action selector="runPageLayout:" target="-1" id="87"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Print…" keyEquivalent="p" id="78">
+                                <connections>
+                                    <action selector="printWebView:" target="-1" id="86"/>
+                                </connections>
+                            </menuItem>
+                        </items>
+                    </menu>
+                </menuItem>
+                <menuItem title="Edit" id="217">
+                    <menu key="submenu" title="Edit" id="205">
+                        <items>
+                            <menuItem title="Undo" keyEquivalent="z" id="207">
+                                <connections>
+                                    <action selector="undo:" target="-1" id="223"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Redo" keyEquivalent="Z" id="215">
+                                <modifierMask key="keyEquivalentModifierMask" shift="YES" command="YES"/>
+                                <connections>
+                                    <action selector="redo:" target="-1" id="231"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem isSeparatorItem="YES" id="206">
+                                <modifierMask key="keyEquivalentModifierMask" command="YES"/>
+                            </menuItem>
+                            <menuItem title="Cut" keyEquivalent="x" id="199">
+                                <connections>
+                                    <action selector="cut:" target="-1" id="228"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Copy" keyEquivalent="c" id="197">
+                                <connections>
+                                    <action selector="copy:" target="-1" id="224"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Paste" keyEquivalent="v" id="203">
+                                <connections>
+                                    <action selector="paste:" target="-1" id="226"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Delete" id="202">
+                                <connections>
+                                    <action selector="delete:" target="-1" id="235"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Select All" keyEquivalent="a" id="198">
+                                <connections>
+                                    <action selector="selectAll:" target="-1" id="232"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem isSeparatorItem="YES" id="214">
+                                <modifierMask key="keyEquivalentModifierMask" command="YES"/>
+                            </menuItem>
+                            <menuItem title="Find" id="218">
+                                <menu key="submenu" title="Find" id="220">
+                                    <items>
+                                        <menuItem title="Find…" tag="1" keyEquivalent="f" id="209">
+                                            <connections>
+                                                <action selector="performTextFinderAction:" target="-1" id="241"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem title="Find Next" tag="2" keyEquivalent="g" id="208">
+                                            <connections>
+                                                <action selector="performTextFinderAction:" target="-1" id="487"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem title="Find Previous" tag="3" keyEquivalent="G" id="213">
+                                            <modifierMask key="keyEquivalentModifierMask" shift="YES" command="YES"/>
+                                            <connections>
+                                                <action selector="performTextFinderAction:" target="-1" id="488"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem title="Use Selection for Find" tag="7" keyEquivalent="e" id="221">
+                                            <connections>
+                                                <action selector="performTextFinderAction:" target="-1" id="489"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem title="Jump to Selection" keyEquivalent="j" id="210">
+                                            <connections>
+                                                <action selector="centerSelectionInVisibleArea:" target="-1" id="245"/>
+                                            </connections>
+                                        </menuItem>
+                                    </items>
+                                </menu>
+                            </menuItem>
+                        </items>
+                    </menu>
+                </menuItem>
+                <menuItem title="View" id="295">
+                    <menu key="submenu" title="View" id="296">
+                        <items>
+                            <menuItem title="Zoom In" keyEquivalent="+" id="555">
+                                <connections>
+                                    <action selector="zoomIn:" target="-1" id="559"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Zoom Out" keyEquivalent="-" id="557">
+                                <connections>
+                                    <action selector="zoomOut:" target="-1" id="560"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Reset Zoom" keyEquivalent="0" id="558">
+                                <connections>
+                                    <action selector="resetZoom:" target="-1" id="561"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Zoom Text Only" id="562">
+                                <modifierMask key="keyEquivalentModifierMask"/>
+                                <connections>
+                                    <action selector="toggleZoomMode:" target="-1" id="564"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Page Scale" id="Hzb-c3-Qfv">
+                                <modifierMask key="keyEquivalentModifierMask"/>
+                                <menu key="submenu" title="Page Scale" id="jdo-5V-3CM">
+                                    <items>
+                                        <menuItem title="100%" state="on" tag="1" keyEquivalent="1" id="wHb-mR-Fv0">
+                                            <connections>
+                                                <action selector="setPageScale:" target="-1" id="uMw-eY-289"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem title="125%" tag="2" keyEquivalent="2" id="u4i-F7-rPb">
+                                            <connections>
+                                                <action selector="setPageScale:" target="-1" id="IbE-Ep-hfc"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem title="150%" tag="3" keyEquivalent="3" id="fwT-Iy-oK9">
+                                            <connections>
+                                                <action selector="setPageScale:" target="-1" id="9c0-eN-0f5"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem title="200%" tag="4" keyEquivalent="4" id="R5e-ct-O2u">
+                                            <connections>
+                                                <action selector="setPageScale:" target="-1" id="mkk-gh-dlN"/>
+                                            </connections>
+                                        </menuItem>
+                                    </items>
+                                </menu>
+                            </menuItem>
+                            <menuItem title="View Scale" id="8UY-Pj-H13">
+                                <modifierMask key="keyEquivalentModifierMask"/>
+                                <menu key="submenu" title="View Scale" id="Ml8-mk-ffu">
+                                    <items>
+                                        <menuItem title="100%" state="on" tag="1" id="EAm-Xn-VrC">
+                                            <modifierMask key="keyEquivalentModifierMask"/>
+                                            <connections>
+                                                <action selector="setViewScale:" target="-1" id="dkW-CI-RG4"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem title="75%" tag="2" id="jcA-I1-Cbq">
+                                            <modifierMask key="keyEquivalentModifierMask"/>
+                                            <connections>
+                                                <action selector="setViewScale:" target="-1" id="BAF-Ym-IqV"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem title="50%" tag="3" id="BRM-D5-YNO">
+                                            <modifierMask key="keyEquivalentModifierMask"/>
+                                            <connections>
+                                                <action selector="setViewScale:" target="-1" id="nXy-2b-9Zz"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem title="25%" tag="4" id="gzk-YK-x0W">
+                                            <modifierMask key="keyEquivalentModifierMask"/>
+                                            <connections>
+                                                <action selector="setViewScale:" target="-1" id="KXK-f6-24N"/>
+                                            </connections>
+                                        </menuItem>
+                                    </items>
+                                </menu>
+                            </menuItem>
+                            <menuItem title="Reload Page" keyEquivalent="r" id="579">
+                                <connections>
+                                    <action selector="reload:" target="-1" id="582"/>
+                                </connections>
+                            </menuItem>
+                        </items>
+                    </menu>
+                </menuItem>
+                <menuItem title="Debug" id="534">
+                    <modifierMask key="keyEquivalentModifierMask"/>
+                    <menu key="submenu" title="Debug" id="535">
+                        <items>
+                            <menuItem title="Show Web Inspector" keyEquivalent="i" id="xso-9z-R4u">
+                                <modifierMask key="keyEquivalentModifierMask" option="YES" command="YES"/>
+                                <connections>
+                                    <action selector="showHideWebInspector:" target="-1" id="Cmx-g7-EPb"/>
+                                </connections>
+                            </menuItem>
+                        </items>
+                    </menu>
+                </menuItem>
+                <menuItem title="Window" id="19">
+                    <menu key="submenu" title="Window" systemMenu="window" id="24">
+                        <items>
+                            <menuItem title="Minimize" keyEquivalent="m" id="23">
+                                <connections>
+                                    <action selector="performMiniaturize:" target="-1" id="37"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem title="Zoom" id="239">
+                                <connections>
+                                    <action selector="performZoom:" target="-1" id="240"/>
+                                </connections>
+                            </menuItem>
+                            <menuItem isSeparatorItem="YES" id="92">
+                                <modifierMask key="keyEquivalentModifierMask" command="YES"/>
+                            </menuItem>
+                            <menuItem title="Bring All to Front" id="5">
+                                <connections>
+                                    <action selector="arrangeInFront:" target="-1" id="39"/>
+                                </connections>
+                            </menuItem>
+                        </items>
+                    </menu>
+                </menuItem>
+            </items>
+            <point key="canvasLocation" x="139" y="-50"/>
+        </menu>
+        <customObject id="494" customClass="BrowserAppDelegate"/>
+    </objects>
+</document>
diff --git a/Tools/Playwright/mac/Playwright_Prefix.pch b/Tools/Playwright/mac/Playwright_Prefix.pch
new file mode 100644
index 0000000000000000000000000000000000000000..ab6e9bce9a41291bb35664c2c63751c3413601f2
--- /dev/null
+++ b/Tools/Playwright/mac/Playwright_Prefix.pch
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef __OBJC__
+#import <Cocoa/Cocoa.h>
+#import <WebKit/WebKit.h>
+#endif
+
+#define ENABLE_LOGGING 0
+
+#if ENABLE_LOGGING
+#define LOG NSLog
+#else
+#define LOG(...) ((void)0)
+#endif
diff --git a/Tools/Playwright/mac/main.m b/Tools/Playwright/mac/main.m
new file mode 100644
index 0000000000000000000000000000000000000000..ba2ca12482c0ab809998131f693c876019c595f1
--- /dev/null
+++ b/Tools/Playwright/mac/main.m
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import <Cocoa/Cocoa.h>
+
+int main(int argc, char *argv[])
+{
+    [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"WebKitLinkedOnOrAfterEverything"];
+
+    return NSApplicationMain(argc,  (const char **) argv);
+}
diff --git a/Tools/Scripts/build-webkit b/Tools/Scripts/build-webkit
index fc0664a6505546f428c7514b9675119b75a62140..14556b3742856ba88d9363957ea97f337fe63191 100755
--- a/Tools/Scripts/build-webkit
+++ b/Tools/Scripts/build-webkit
@@ -246,7 +246,7 @@ if (isAppleCocoaWebKit()) {
     push @projects, ("Source/WebKit");
 
     if (!isIOSWebKit()) {
-        push @projects, ("Tools/MiniBrowser");
+        push @projects, ("Tools/Playwright");
 
         # WebInspectorUI must come after JavaScriptCore and WebCore but before WebKit and WebKit2
         my $webKitIndex = first { $projects[$_] eq "Source/WebKitLegacy" } 0..$#projects;
diff --git a/Tools/WebKitTestRunner/TestController.cpp b/Tools/WebKitTestRunner/TestController.cpp
index 213b7eb71346f0efa4f148cc3dc599b044a2f124..8ba65214d478a9fe2710b7692fed3637a7ba22fa 100644
--- a/Tools/WebKitTestRunner/TestController.cpp
+++ b/Tools/WebKitTestRunner/TestController.cpp
@@ -718,7 +718,8 @@ void TestController::createWebViewWithOptions(const TestOptions& options)
         0, // didResignInputElementStrongPasswordAppearance
         0, // requestStorageAccessConfirm
         shouldAllowDeviceOrientationAndMotionAccess,
-        runWebAuthenticationPanel
+        runWebAuthenticationPanel,
+        0 // handleJavaScriptDialog
     };
     WKPageSetPageUIClient(m_mainWebView->page(), &pageUIClient.base);
 
diff --git a/Tools/WebKitTestRunner/win/EventSenderProxyWin.cpp b/Tools/WebKitTestRunner/win/EventSenderProxyWin.cpp
index 06f19261b387ce02a44c319bd7016e824847ad24..c4e2f8f8816b06a105c18872e735ae4dbca6fe68 100644
--- a/Tools/WebKitTestRunner/win/EventSenderProxyWin.cpp
+++ b/Tools/WebKitTestRunner/win/EventSenderProxyWin.cpp
@@ -312,4 +312,59 @@ void EventSenderProxy::keyDown(WKStringRef keyRef, WKEventModifiers wkModifiers,
         SetKeyboardState(keyState);
 }
 
+void EventSenderProxy::addTouchPoint(int, int)
+{
+    notImplemented();
+}
+
+void EventSenderProxy::updateTouchPoint(int, int, int)
+{
+    notImplemented();
+}
+
+void EventSenderProxy::setTouchModifier(WKEventModifiers, bool)
+{
+    notImplemented();
+}
+
+void EventSenderProxy::setTouchPointRadius(int, int)
+{
+    notImplemented();
+}
+
+void EventSenderProxy::touchStart()
+{
+    notImplemented();
+}
+
+void EventSenderProxy::touchMove()
+{
+    notImplemented();
+}
+
+void EventSenderProxy::touchEnd()
+{
+    notImplemented();
+}
+
+void EventSenderProxy::touchCancel()
+{
+    notImplemented();
+}
+
+void EventSenderProxy::clearTouchPoints()
+{
+    notImplemented();
+}
+
+void EventSenderProxy::releaseTouchPoint(int)
+{
+    notImplemented();
+}
+
+void EventSenderProxy::cancelTouchPoint(int)
+{
+    notImplemented();
+}
+
 } // namespace WTR
diff --git a/Tools/wpe/backends/CMakeLists.txt b/Tools/wpe/backends/CMakeLists.txt
index 6456f4408c95b22246817912d430c42fc982932b..a08cc6da1936127a516fe0e95007de9cd18bdb02 100644
--- a/Tools/wpe/backends/CMakeLists.txt
+++ b/Tools/wpe/backends/CMakeLists.txt
@@ -10,6 +10,7 @@ file(MAKE_DIRECTORY ${DERIVED_SOURCES_WPETOOLINGBACKENDS_DIR})
 set(WPEToolingBackends_SOURCES
     ${DERIVED_SOURCES_WPETOOLINGBACKENDS_DIR}/xdg-shell-unstable-v6-protocol.c
     ${TOOLS_DIR}/wpe/backends/HeadlessViewBackend.cpp
+    ${TOOLS_DIR}/wpe/backends/NullViewBackend.cpp
     ${TOOLS_DIR}/wpe/backends/ViewBackend.cpp
     ${TOOLS_DIR}/wpe/backends/WebKitAccessibleApplication.cpp
     ${TOOLS_DIR}/wpe/backends/WindowViewBackend.cpp
diff --git a/Tools/wpe/backends/NullViewBackend.cpp b/Tools/wpe/backends/NullViewBackend.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..033ff802d3971a455667cd64c0e68dd10f448aa7
--- /dev/null
+++ b/Tools/wpe/backends/NullViewBackend.cpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "NullViewBackend.h"
+
+#include <wpe/fdo-egl.h>
+
+namespace WPEToolingBackends {
+
+NullViewBackend::NullViewBackend()
+    : ViewBackend(1, 1)
+{
+    static struct wpe_view_backend_exportable_fdo_egl_client exportableClient = { nullptr, nullptr, nullptr, nullptr, nullptr };
+    m_exportable = wpe_view_backend_exportable_fdo_egl_create(&exportableClient, this, 1, 1);
+    initializeAccessibility();
+    addActivityState(wpe_view_activity_state_visible | wpe_view_activity_state_focused | wpe_view_activity_state_in_window);
+}
+
+} // namespace WPEToolingBackends
diff --git a/Tools/wpe/backends/NullViewBackend.h b/Tools/wpe/backends/NullViewBackend.h
new file mode 100644
index 0000000000000000000000000000000000000000..c4489294acfe73adcb3593f2d54a3be625307f28
--- /dev/null
+++ b/Tools/wpe/backends/NullViewBackend.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) Microsoft Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "ViewBackend.h"
+#include <cairo.h>
+#include <glib.h>
+#include <unordered_map>
+
+namespace WPEToolingBackends {
+
+class NullViewBackend final : public ViewBackend {
+public:
+    NullViewBackend();
+    virtual ~NullViewBackend() = default;
+private:
+    void displayBuffer(struct wpe_fdo_egl_exported_image*) override { };
+#if WPE_FDO_CHECK_VERSION(1, 5, 0)
+    void displayBuffer(struct wpe_fdo_shm_exported_buffer*) override { };
+#endif
+};
+
+} // namespace WPEToolingBackends