playwright/browser_patches/webkit/patches/bootstrap.diff

diff --git a/Source/JavaScriptCore/CMakeLists.txt b/Source/JavaScriptCore/CMakeLists.txt
index a5c74c12c14ac9447b72c4e458d2e88963315d49..d2877184c6e5cec4a5c35d61d84711e1fae436d7 100644
--- a/Source/JavaScriptCore/CMakeLists.txt
+++ b/Source/JavaScriptCore/CMakeLists.txt
@@ -1165,22 +1165,27 @@ set(JavaScriptCore_INSPECTOR_DOMAINS
     ${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/IndexedDB.json
+    ${JAVASCRIPTCORE_DIR}/inspector/protocol/Input.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Inspector.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/LayerTree.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Memory.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Network.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Page.json
+    ${JAVASCRIPTCORE_DIR}/inspector/protocol/Playwright.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Recording.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Runtime.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/ScriptProfiler.json
+    ${JAVASCRIPTCORE_DIR}/inspector/protocol/Screencast.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Security.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/ServiceWorker.json
     ${JAVASCRIPTCORE_DIR}/inspector/protocol/Target.json
diff --git a/Source/JavaScriptCore/DerivedSources.make b/Source/JavaScriptCore/DerivedSources.make
index 10f9fec51dce48686ff8745beaa4b5b5d5b1033d..770548a5dbfe9650f3d06551556f00b7305b8c53 100644
--- a/Source/JavaScriptCore/DerivedSources.make
+++ b/Source/JavaScriptCore/DerivedSources.make
@@ -260,22 +260,27 @@ INSPECTOR_DOMAINS := \
     $(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/IndexedDB.json \
+    $(JavaScriptCore)/inspector/protocol/Input.json \
     $(JavaScriptCore)/inspector/protocol/Inspector.json \
     $(JavaScriptCore)/inspector/protocol/LayerTree.json \
     $(JavaScriptCore)/inspector/protocol/Memory.json \
     $(JavaScriptCore)/inspector/protocol/Network.json \
     $(JavaScriptCore)/inspector/protocol/Page.json \
+    $(JavaScriptCore)/inspector/protocol/Playwright.json \
     $(JavaScriptCore)/inspector/protocol/Recording.json \
     $(JavaScriptCore)/inspector/protocol/Runtime.json \
     $(JavaScriptCore)/inspector/protocol/ScriptProfiler.json \
+    $(JavaScriptCore)/inspector/protocol/Screencast.json \
     $(JavaScriptCore)/inspector/protocol/Security.json \
     $(JavaScriptCore)/inspector/protocol/ServiceWorker.json \
     $(JavaScriptCore)/inspector/protocol/Target.json \
diff --git a/Source/JavaScriptCore/bindings/ScriptValue.cpp b/Source/JavaScriptCore/bindings/ScriptValue.cpp
index 6b853c931f1dce9253bbac06a95e6aac527cf25a..bb50bfb871ace62ef84be62c7564f2e3f27dc2bd 100644
--- a/Source/JavaScriptCore/bindings/ScriptValue.cpp
+++ b/Source/JavaScriptCore/bindings/ScriptValue.cpp
@@ -79,7 +79,10 @@ 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/InjectedScriptSource.js b/Source/JavaScriptCore/inspector/InjectedScriptSource.js
index cd593a24af4fe24ba59577b73b26947765edcc32..1f7a04d72065dbd60761c1a72f3254f953d3b9a9 100644
--- a/Source/JavaScriptCore/inspector/InjectedScriptSource.js
+++ b/Source/JavaScriptCore/inspector/InjectedScriptSource.js
@@ -136,7 +136,7 @@ let InjectedScript = class InjectedScript
             return;
         }
 
-        if (!(promiseObject instanceof Promise)) {
+        if (InjectedScriptHost.internalConstructorName(promiseObject) !== 'Promise') {
             callback("Object with given id is not a Promise");
             return;
         }
diff --git a/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.cpp b/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.cpp
index 693e8b25c73778340e8394046786d9318a8a0924..4be62e0aca82895a96449175adb1af10e7b9daec 100644
--- a/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.cpp
+++ b/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.cpp
@@ -101,7 +101,7 @@ void BackendDispatcher::registerDispatcherForDomain(const String& domain, Supple
     m_dispatchers.set(domain, dispatcher);
 }
 
-void BackendDispatcher::dispatch(const String& message)
+void BackendDispatcher::dispatch(const String& message, Interceptor&& interceptor)
 {
     Ref<BackendDispatcher> protect(*this);
 
@@ -142,6 +142,9 @@ void BackendDispatcher::dispatch(const String& message)
         }
     }
 
+    if (interceptor && interceptor(messageObject) == InterceptionResult::Intercepted)
+        return;
+
     {
         // We could be called re-entrantly from a nested run loop, so restore the previous id.
         SetForScope<Optional<long>> scopedRequestId(m_currentRequestId, requestId);
diff --git a/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.h b/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.h
index 95d9d81188e735e8f1b70cc0deee2682cb6714f0..fbab25a07bf35c49faf026a3dfaccd50f50d1ab8 100644
--- a/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.h
+++ b/Source/JavaScriptCore/inspector/InspectorBackendDispatcher.h
@@ -82,7 +82,10 @@ public:
     };
 
     void registerDispatcherForDomain(const String& domain, SupplementalBackendDispatcher*);
-    void dispatch(const String& message);
+
+    enum class InterceptionResult { Intercepted, Continue };
+    using Interceptor = WTF::Function<InterceptionResult(const RefPtr<JSON::Object>&)>;
+    void dispatch(const String& message, 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 b929ddffe29c3fb088ab6714087c99302c275214..2670ff3ba9b15afd2bb99993c3240c49b24907f5 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) final;
     void resume(ErrorString&, const String& targetId) final;
     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/DOM.json b/Source/JavaScriptCore/inspector/protocol/DOM.json
index f3a7753702995ebc54312ead0b0c028a58bb19b9..869e06b61f31356dd10c38fc5cae519fa40c2b9e 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": [
@@ -508,7 +528,9 @@
             "description": "Resolves JavaScript node object for given node id.",
             "targetTypes": ["page"],
             "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": [
@@ -575,6 +597,45 @@
             "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..3f28f8e41b39c517369c8ca69415486a75657489
--- /dev/null
+++ b/Source/JavaScriptCore/inspector/protocol/Emulation.json
@@ -0,0 +1,51 @@
+{
+    "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 }
+            ]
+        },
+        {
+            "name": "grantPermissions",
+            "parameters": [
+                { "name": "origin", "type": "string" },
+                { "name": "permissions", "type": "array", "items": { "type": "string" } }
+            ],
+            "description": "Overrides the permissions."
+        },
+        {
+            "name": "resetPermissions",
+            "description": "Clears permission overrides."
+        }
+    ]
+}
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 f2425dd6afc0efbf1d115220fd4246afe2fb92e1..98a7adfb72c7a7f1b67df37bea6bf7c48a2c80d9 100644
--- a/Source/JavaScriptCore/inspector/protocol/Network.json
+++ b/Source/JavaScriptCore/inspector/protocol/Network.json
@@ -236,7 +236,8 @@
             "description": "Enable interception of network requests.",
             "targetTypes": ["page"],
             "parameters": [
-                { "name": "enabled", "type": "boolean" }
+                { "name": "enabled", "type": "boolean" },
+                { "name": "interceptRequests", "type": "boolean", "optional": true }
             ]
         },
         {
@@ -266,7 +267,18 @@
             "description": "Continue an interception with no modifications.",
             "targetTypes": ["page"],
             "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", "$ref": "RequestId", "description": "Identifier for the intercepted Network request." },
+                { "name": "reason", "type": "string", "description": "Deliver error reason for the request." }
             ]
         },
         {
@@ -275,13 +287,20 @@
             "targetTypes": ["page"],
             "parameters": [
                 { "name": "requestId", "$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", "$ref": "Headers", "optional": true, "description": "HTTP response headers. Pass through original values if unmodified." }
             ]
+        },
+        {
+            "name": "setEmulateOfflineState",
+            "description": "Emulate offline state overriding the actual state.",
+            "parameters": [
+                { "name": "offline", "type": "boolean", "description": "True to emulate offline." }
+            ]
         }
     ],
     "events": [
@@ -366,6 +385,14 @@
                 { "name": "response", "$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 3b8fa18bd7e8d95d7e8f95b442afc63e550ce63a..edeabe67bd568be7fbe66781fce61a42644b0ca3 100644
--- a/Source/JavaScriptCore/inspector/protocol/Page.json
+++ b/Source/JavaScriptCore/inspector/protocol/Page.json
@@ -27,7 +27,7 @@
         {
             "id": "ResourceType",
             "type": "string",
-            "enum": ["Document", "StyleSheet", "Image", "Font", "Script", "XHR", "Fetch", "Ping", "Beacon", "WebSocket", "Other"],
+            "enum": ["Document", "StyleSheet", "Image", "Font", "Script", "XHR", "Fetch", "Ping", "Beacon", "WebSocket", "EventSource", "Other"],
             "description": "Resource type as it was perceived by the rendering engine."
         },
         {
@@ -112,6 +112,41 @@
                 { "name": "secure", "type": "boolean", "description": "True if cookie is secure." },
                 { "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": [
@@ -131,6 +166,14 @@
                 { "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.",
@@ -270,6 +313,20 @@
                 { "name": "appearance", "$ref": "Appearance", "description": "Appearance name to force. Empty string disables the override." }
             ]
         },
+        {
+            "name": "setTimeZone",
+            "description": "Enables time zone emulation.",
+            "parameters": [
+                { "name": "timeZone", "type": "string", "optional": true }
+            ]
+        },
+        {
+            "name": "setTouchEmulationEnabled",
+            "description": "Enables touch events on platforms that lack them.",
+            "parameters": [
+                {"name": "enabled", "type": "boolean", "description": "Whether touch should be enabled."}
+            ]
+        },
         {
             "name": "snapshotNode",
             "description": "Capture a snapshot of the specified node that does not include unrelated layers.",
@@ -304,6 +361,77 @@
             "returns": [
                 { "name": "data", "type": "string", "description": "Base64-encoded web archive." }
             ]
+        },
+        {
+            "name": "insertText",
+            "description": "Insert text into the current selection of the page.",
+            "parameters": [
+                { "name": "text", "type": "string", "description": "Text to insert." }
+            ]
+        },
+        {
+            "name": "accessibilitySnapshot",
+            "description": "Serializes and returns all of the accessibility nodes of the page.",
+            "parameters": [
+                { "name": "objectId", "type": "string", "optional": true, "description": "Object Id of a node to find in the accessibility tree."}
+            ],
+            "returns": [
+                { "name": "axNode", "$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" }
+            ]
+        },
+        {
+            "name": "setOrientationOverride",
+            "description": "Overrides window.orientation with provided value.",
+            "parameters": [
+                { "name": "angle", "type": "integer", "optional": true }
+            ]
+        },
+        {
+            "name": "setActivityPaused",
+            "description": "Pauses page activity (active objects, animations).",
+            "parameters": [
+                { "name": "paused", "type": "boolean" }
+            ]
         }
     ],
     "events": [
@@ -311,14 +439,16 @@
             "name": "domContentEventFired",
             "targetTypes": ["page"],
             "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",
             "targetTypes": ["page"],
             "parameters": [
-                { "name": "timestamp", "type": "number" }
+              { "name": "timestamp", "type": "number" },
+              { "name": "frameId", "$ref": "Network.FrameId", "description": "Id of the frame that has fired load event." }
             ]
         },
         {
@@ -328,6 +458,14 @@
                 { "name": "frame", "$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.",
@@ -367,6 +505,22 @@
                 { "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.",
@@ -375,6 +529,28 @@
             "parameters": [
                 { "name": "appearance", "$ref": "Appearance", "description": "Name of the appearance that is active (not considering any forced appearance.)" }
             ]
+        },
+        {
+          "name": "willRequestOpenWindow",
+          "description": "Fired when page tries to open a new window.",
+          "parameters": [
+              { "name": "url", "type": "string" }
+          ]
+        },
+        {
+          "name": "didRequestOpenWindow",
+          "description": "Fired after page did try to open a new window.",
+          "parameters": [
+              { "name": "opened", "type": "boolean" }
+          ]
+        },
+        {
+            "name": "fileChooserOpened",
+            "description": "Fired when the page shows file chooser for it's <input type=file>.",
+            "parameters": [
+                { "name": "frameId", "$ref": "Network.FrameId", "description": "Frame where file chooser is opened." },
+                { "name": "element", "$ref": "Runtime.RemoteObject", "description": "Input element." }
+            ]
         }
     ]
 }
diff --git a/Source/JavaScriptCore/inspector/protocol/Playwright.json b/Source/JavaScriptCore/inspector/protocol/Playwright.json
new file mode 100644
index 0000000000000000000000000000000000000000..dd4c318ec4b9b49ce937266ba899e54f8e6fa932
--- /dev/null
+++ b/Source/JavaScriptCore/inspector/protocol/Playwright.json
@@ -0,0 +1,244 @@
+{
+    "domain": "Playwright",
+    "availability": ["web"],
+    "types": [
+        {
+            "id": "ContextID",
+            "type": "string",
+            "description": "Id of Browser context."
+        },
+        {
+            "id": "PageProxyID",
+            "type": "string",
+            "description": "Id of WebPageProxy."
+        },
+        {
+            "id": "CookieSameSitePolicy",
+            "type": "string",
+            "enum": ["None", "Lax", "Strict"],
+            "description": "Same-Site policy of a cookie."
+        },
+        {
+            "id": "Cookie",
+            "type": "object",
+            "description": "Cookie object",
+            "properties": [
+                { "name": "name", "type": "string", "description": "Cookie name." },
+                { "name": "value", "type": "string", "description": "Cookie value." },
+                { "name": "domain", "type": "string", "description": "Cookie domain." },
+                { "name": "path", "type": "string", "description": "Cookie path." },
+                { "name": "expires", "type": "number", "description": "Cookie expires." },
+                { "name": "httpOnly", "type": "boolean", "description": "True if cookie is http-only." },
+                { "name": "secure", "type": "boolean", "description": "True if cookie is secure." },
+                { "name": "session", "type": "boolean", "description": "True if cookie is session cookie." },
+                { "name": "sameSite", "$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", "$ref": "CookieSameSitePolicy", "optional": true, "description": "Cookie Same-Site policy." }
+            ]
+        },
+        {
+            "id": "Geolocation",
+            "type": "object",
+            "description": "Geolocation",
+            "properties": [
+                { "name": "timestamp", "type": "number", "description": "Mock latitude" },
+                { "name": "latitude", "type": "number", "description": "Mock latitude" },
+                { "name": "longitude", "type": "number", "description": "Mock longitude" },
+                { "name": "accuracy", "type": "number", "description": "Mock accuracy" }
+            ]
+        }
+    ],
+    "commands": [
+        {
+            "name": "enable"
+        },
+        {
+            "name": "disable"
+        },
+        {
+            "name": "close",
+            "async": true,
+            "description": "Close browser."
+        },
+        {
+            "name": "createContext",
+            "description": "Creates new ephemeral browser context.",
+            "parameters": [
+                { "name": "proxyServer", "type": "string", "optional": true, "description": "Proxy server, similar to the one passed to --proxy-server" },
+                { "name": "proxyBypassList", "type": "string", "optional": true, "description": "Proxy bypass list, similar to the one passed to --proxy-bypass-list" }
+            ],
+            "returns": [
+                { "name": "browserContextId", "$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": "setLanguages",
+            "description": "Allows to set locale language for context.",
+            "parameters": [
+                { "name": "languages", "type": "array", "items": { "type": "string" } },
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "Browser context id." }
+            ]
+        },
+        {
+            "name": "setDownloadBehavior",
+            "description": "Allows to override download behavior.",
+            "parameters": [
+                { "name": "behavior", "optional": true, "type": "string", "enum": ["allow", "deny"] },
+                { "name": "downloadPath", "optional": true, "type": "string" },
+                { "name": "browserContextId", "$ref": "ContextID", "optional": true, "description": "Browser context id." }
+            ]
+        }
+    ],
+    "events": [
+        {
+            "name": "pageProxyCreated",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "description": "Unique identifier of the context." },
+                { "name": "pageProxyId", "$ref": "PageProxyID" },
+                { "name": "openerId", "$ref": "PageProxyID", "optional": true, "description": "Unique identifier of the opening page. Only set for pages created by window.open()." }
+            ]
+        },
+        {
+            "name": "pageProxyDestroyed",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "description": "Unique identifier of the context." },
+                { "name": "pageProxyId", "$ref": "PageProxyID" }
+            ]
+        },
+        {
+            "name": "provisionalLoadFailed",
+            "description": "Fired when provisional load fails.",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "description": "Unique identifier of the context." },
+                { "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." }
+            ]
+        },
+        {
+          "name": "windowOpen",
+          "description": "Fired when page opens a new window.",
+          "parameters": [
+              { "name": "browserContextId", "$ref": "ContextID", "description": "Unique identifier of the context." },
+              { "name": "pageProxyId", "$ref": "PageProxyID", "description": "Unique identifier of the page proxy." },
+              { "name": "url", "type": "string" },
+              { "name": "windowFeatures", "type": "array", "items": { "type": "string" } }
+          ]
+        },
+        {
+            "name": "downloadCreated",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "description": "Unique identifier of the context." },
+                { "name": "pageProxyId", "$ref": "PageProxyID", "description": "Unique identifier of the page proxy." },
+                { "name": "frameId", "$ref": "Network.FrameId", "description": "Unique identifier of the originating frame." },
+                { "name": "uuid", "type": "string" },
+                { "name": "url", "type": "string" }
+            ]
+        },
+        {
+            "name": "downloadFilenameSuggested",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "description": "Unique identifier of the context." },
+                { "name": "uuid", "type": "string" },
+                { "name": "suggestedFilename", "type": "string" }
+            ]
+        },
+        {
+            "name": "downloadFinished",
+            "parameters": [
+                { "name": "browserContextId", "$ref": "ContextID", "description": "Unique identifier of the context." },
+                { "name": "uuid", "type": "string" },
+                { "name": "error", "type": "string" }
+            ]
+        }
+    ]
+}
diff --git a/Source/JavaScriptCore/inspector/protocol/Screencast.json b/Source/JavaScriptCore/inspector/protocol/Screencast.json
new file mode 100644
index 0000000000000000000000000000000000000000..5da42efd27406d66ad6a2f23e27d79f1512a7a3a
--- /dev/null
+++ b/Source/JavaScriptCore/inspector/protocol/Screencast.json
@@ -0,0 +1,53 @@
+{
+    "domain": "Screencast",
+    "availability": ["web"],
+    "types": [
+        {
+            "id": "ImageFormat",
+            "type": "string",
+            "enum": ["jpeg", "png"]
+        }
+    ],
+    "commands": [
+        {
+            "name": "start",
+            "description": "Starts screencast.",
+            "parameters": [
+                { "name": "format", "$ref": "ImageFormat", "description": "Frame data format." },
+                { "name": "quality", "type": "integer", "optional": true, "description": "For JPEG quality from range [0..100]. Ignored for PNG." }
+            ]
+        },
+        {
+            "name": "stop",
+            "description": "Stops screencast."
+        },
+        {
+            "name": "frameAck",
+            "description": "Sent by the client when a frame has been received."
+        },
+        {
+            "name": "startVideoRecording",
+            "description": "Starts recoring video to speified file.",
+            "parameters": [
+                { "name": "file", "type": "string", "description": "Output file location." },
+                { "name": "width", "type": "integer" },
+                { "name": "height", "type": "integer" },
+                { "name": "scale", "type": "number", "optional": true }
+            ]
+        },
+        {
+            "name": "stopVideoRecording",
+            "async": true,
+            "description": "Stops recoding video. Returns after the file has been closed."
+        }
+    ],
+    "events": [
+        {
+            "name": "frame",
+            "description": "Event describing captured frame. The client is expcted to send frameAck in response.",
+            "parameters": [
+                { "name": "data", "type": "string", "description": "Base64-encoded image." }
+            ]
+        }
+    ]
+}
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 638612413466efc87b737e8a81042ed07ca12703..6f9e518ff0bfa2a6228675d25b6b785f1ed3022a 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",
@@ -33,7 +33,8 @@
             "parameters": [
                 { "name": "workerId", "type": "string" },
                 { "name": "url", "type": "string" },
-                { "name": "name", "type": "string" }
+                { "name": "name", "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 7dfbc367cf4fb4298adf611d12c6ae2f46761385..f3c180ad03478634caa4f5db863bde10c0fc629e 100644
--- a/Source/JavaScriptCore/runtime/IntlDateTimeFormat.cpp
+++ b/Source/JavaScriptCore/runtime/IntlDateTimeFormat.cpp
@@ -34,6 +34,7 @@
 #include <unicode/ucal.h>
 #include <unicode/udatpg.h>
 #include <unicode/uenum.h>
+#include <wtf/DateMath.h>
 #include <wtf/text/StringBuilder.h>
 #include <wtf/unicode/icu/ICUHelpers.h>
 
@@ -102,6 +103,10 @@ static ALWAYS_INLINE bool isUTCEquivalent(StringView timeZone)
 // https://tc39.es/ecma402/#sec-defaulttimezone
 static String defaultTimeZone()
 {
+    String tz = WTF::timeZoneForAutomation();
+    if (!tz.isEmpty())
+        return tz;
+
     String canonical;
 
     Vector<UChar, 32> buffer;
diff --git a/Source/WTF/wtf/DateMath.cpp b/Source/WTF/wtf/DateMath.cpp
index af92f674770349cc8e7be9a53b1cee6e7840e781..f0a960db046292a3505d339a333f03098f3d8418 100644
--- a/Source/WTF/wtf/DateMath.cpp
+++ b/Source/WTF/wtf/DateMath.cpp
@@ -76,9 +76,14 @@
 #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/NeverDestroyed.h>
+#include <wtf/ThreadSpecific.h>
 #include <wtf/text/StringBuilder.h>
+#include <wtf/unicode/UTF8Conversion.h>
 
 #if OS(WINDOWS)
 #include <windows.h>
@@ -92,6 +97,18 @@ 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" };
@@ -318,6 +335,14 @@ 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
@@ -1019,4 +1044,65 @@ 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 246ba67c764b629042a7927d24fe89b049d82a0b..68d536878d1f0ba832d1c1d3e36e10b8227bbfac 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/PlatformEnable.h b/Source/WTF/wtf/PlatformEnable.h
index f70cfc0c471410960d02e2a11205deecf722786f..b95cff9d62e01ac25f0260ca16cd3cbc2917008a 100644
--- a/Source/WTF/wtf/PlatformEnable.h
+++ b/Source/WTF/wtf/PlatformEnable.h
@@ -406,7 +406,7 @@
 #endif
 
 #if !defined(ENABLE_ORIENTATION_EVENTS)
-#define ENABLE_ORIENTATION_EVENTS 0
+#define ENABLE_ORIENTATION_EVENTS 1
 #endif
 
 #if OS(WINDOWS)
diff --git a/Source/WTF/wtf/PlatformHave.h b/Source/WTF/wtf/PlatformHave.h
index 7a658805bf95d0b35f9c10e85b18a60dae296dd3..3d343783afa64230c6eac5e62df72f8634fcd048 100644
--- a/Source/WTF/wtf/PlatformHave.h
+++ b/Source/WTF/wtf/PlatformHave.h
@@ -342,7 +342,7 @@
 #define HAVE_NSHTTPCOOKIESTORAGE__INITWITHIDENTIFIER_WITH_INACCURATE_NULLABILITY 1
 #endif
 
-#if PLATFORM(MAC) || PLATFORM(IOS) || PLATFORM(MACCATALYST)
+#if PLATFORM(MAC) || 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/Sources.txt b/Source/WebCore/Sources.txt
index 24db8fd2c31d9149d62b969a95a3648ed65570ef..d59a58d2475880d8312610c66e265bfb6027a634 100644
--- a/Source/WebCore/Sources.txt
+++ b/Source/WebCore/Sources.txt
@@ -1451,6 +1451,7 @@ inspector/agents/InspectorLayerTreeAgent.cpp
 inspector/agents/InspectorMemoryAgent.cpp
 inspector/agents/InspectorNetworkAgent.cpp
 inspector/agents/InspectorPageAgent.cpp
+inspector/agents/InspectorScreencastAgent.cpp
 inspector/agents/InspectorTimelineAgent.cpp
 inspector/agents/InspectorWorkerAgent.cpp
 inspector/agents/WebConsoleAgent.cpp
diff --git a/Source/WebCore/SourcesCocoa.txt b/Source/WebCore/SourcesCocoa.txt
index a25286e0a68316e017c9140b90482bde0859102b..81bc29f2b83e739a561cb3e4742df4a64ec64da2 100644
--- a/Source/WebCore/SourcesCocoa.txt
+++ b/Source/WebCore/SourcesCocoa.txt
@@ -670,7 +670,7 @@ 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 c97ef52bf50e48612037ed6ccf57344c0383bcb4..f028574572b2d87733904cc081c96ec0e9a15a5a 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 5265db58382a89060b363156bf8f17f4032b5881..eec588cf50302c89af8b35fe43452a4dd04483b6 100644
--- a/Source/WebCore/WebCore.xcodeproj/project.pbxproj
+++ b/Source/WebCore/WebCore.xcodeproj/project.pbxproj
@@ -5030,6 +5030,14 @@
 		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, ); }; };
 		F12171F616A8CF0B000053CA /* WebVTTElement.h in Headers */ = {isa = PBXBuildFile; fileRef = F12171F416A8BC63000053CA /* WebVTTElement.h */; };
 		F32BDCD92363AACA0073B6AE /* UserGestureEmulationScope.h in Headers */ = {isa = PBXBuildFile; fileRef = F32BDCD72363AACA0073B6AE /* UserGestureEmulationScope.h */; };
 		F344C7141125B82C00F26EEE /* InspectorFrontendClient.h in Headers */ = {isa = PBXBuildFile; fileRef = F344C7121125B82C00F26EEE /* InspectorFrontendClient.h */; settings = {ATTRIBUTES = (Private, ); }; };
@@ -15730,6 +15738,14 @@
 		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>"; };
@@ -21055,7 +21071,12 @@
 				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 */,
@@ -26345,7 +26366,9 @@
 				B2C3D9EC0D006C1D00EF6F26 /* text */,
 				E1EE8B6B2412B2A700E794D6 /* xr */,
 				DFDB912CF8E88A6DA1AD264F /* AbortableTaskQueue.h */,
+				F050E16623AC9C070011CE47 /* PlatformTouchEvent.h */,
 				49AE2D94134EE5F90072920A /* CalculationValue.cpp */,
+				F050E17623AD70C40011CE47 /* PlatformTouchPoint.h */,
 				49AE2D95134EE5F90072920A /* CalculationValue.h */,
 				C330A22113EC196B0000B45B /* ColorChooser.h */,
 				C37CDEBC149EF2030042090D /* ColorChooserClient.h */,
@@ -28728,6 +28751,7 @@
 				BCCFBAE70B5152ED0001F1D7 /* DocumentParser.h */,
 				AD6E71AA1668899D00320C13 /* DocumentSharedObjectPool.cpp */,
 				AD6E71AB1668899D00320C13 /* DocumentSharedObjectPool.h */,
+				F050E17323AD6A800011CE47 /* DocumentTouch.cpp */,
 				6BDB5DC1227BD3B800919770 /* DocumentStorageAccess.cpp */,
 				6BDB5DC0227BD3B800919770 /* DocumentStorageAccess.h */,
 				6BDB5DC5227CA0EB00919770 /* DocumentStorageAccess.idl */,
@@ -29612,6 +29636,7 @@
 				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 */,
@@ -31493,6 +31518,7 @@
 				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 */,
@@ -33422,9 +33448,11 @@
 				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 */,
@@ -34322,6 +34350,7 @@
 				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 */,
@@ -34389,6 +34418,7 @@
 				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 */,
@@ -34467,6 +34497,7 @@
 				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 */,
@@ -34999,6 +35030,7 @@
 				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/accessibility/AccessibilityObject.cpp b/Source/WebCore/accessibility/AccessibilityObject.cpp
index 3f800102457083c873d9bf81592bbb085cb70460..387c77e51b8268d39757608faa6f3f1f98ddd442 100644
--- a/Source/WebCore/accessibility/AccessibilityObject.cpp
+++ b/Source/WebCore/accessibility/AccessibilityObject.cpp
@@ -58,6 +58,7 @@
 #include "HTMLParserIdioms.h"
 #include "HTMLTextAreaElement.h"
 #include "HitTestResult.h"
+#include "InspectorInstrumentation.h"
 #include "LocalizedStrings.h"
 #include "MathMLNames.h"
 #include "NodeList.h"
@@ -3250,10 +3251,15 @@ AccessibilityObjectInclusion AccessibilityObject::defaultObjectInclusion() const
     
     if (useParentData ? m_isIgnoredFromParentData.isPresentationalChildOfAriaRole : isPresentationalChildOfAriaRole())
         return AccessibilityObjectInclusion::IgnoreObject;
-    
-    return accessibilityPlatformIncludesObject();
+
+    AccessibilityObjectInclusion platformBehavior = accessibilityPlatformIncludesObject();
+    if (platformBehavior != AccessibilityObjectInclusion::DefaultBehavior) {
+        if (auto* page = this->page())
+            InspectorInstrumentation::maybeOverrideDefaultObjectInclusion(*page, platformBehavior);
+    }
+    return platformBehavior;
 }
-    
+
 bool AccessibilityObject::accessibilityIsIgnored() const
 {
     AXComputedObjectAttributeCache* attributeCache = nullptr;
diff --git a/Source/WebCore/css/MediaQueryEvaluator.cpp b/Source/WebCore/css/MediaQueryEvaluator.cpp
index 8118b7ab3c50b3ced8120fc106dce9c73141afe4..2aea3ba07eae2a23b6364074d253356165757549 100644
--- a/Source/WebCore/css/MediaQueryEvaluator.cpp
+++ b/Source/WebCore/css/MediaQueryEvaluator.cpp
@@ -388,7 +388,7 @@ 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;
@@ -506,7 +506,7 @@ 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;
 
@@ -521,8 +521,10 @@ 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 8f71781a258167280f2ae9a8fcd2b79a7e888f12..c8f4bf45765345fd4abd777e2c4975372325c6f4 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"
@@ -204,6 +205,11 @@ 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 a595c13494442c6a69c4f24b1347f057b770211b..27ff50024dec6bfcd43d96a215777696c23e74e9 100644
--- a/Source/WebCore/inspector/InspectorController.cpp
+++ b/Source/WebCore/inspector/InspectorController.cpp
@@ -84,6 +84,9 @@
 #include <JavaScriptCore/JSLock.h>
 #include <wtf/Stopwatch.h>
 
+#if PLATFORM(WPE) || PLATFORM(WIN)
+#include "InspectorScreencastAgent.h"
+#endif
 #if ENABLE(REMOTE_INSPECTOR)
 #include "PageDebuggable.h"
 #endif
@@ -185,6 +188,9 @@ void InspectorController::createLazyAgents()
     m_agents.append(makeUnique<PageHeapAgent>(pageContext));
     m_agents.append(makeUnique<PageAuditAgent>(pageContext));
     m_agents.append(makeUnique<InspectorCanvasAgent>(pageContext));
+#if PLATFORM(WPE) || PLATFORM(WIN)
+    m_agents.append(makeUnique<InspectorScreencastAgent>(pageContext));
+#endif
     m_agents.append(makeUnique<InspectorTimelineAgent>(pageContext));
     m_agents.append(makeUnique<InspectorAnimationAgent>(pageContext));
 
@@ -371,8 +377,8 @@ void InspectorController::inspect(Node* node)
     if (!enabled())
         return;
 
-    if (!hasRemoteFrontend())
-        show();
+    // HACK: Always attempt to show inspector even if there is a remote connection.
+    show();
 
     ensureDOMAgent().inspect(node);
 }
@@ -505,6 +511,13 @@ JSC::VM& InspectorController::vm()
     return commonVM();
 }
 
+// Playwright begin
+void InspectorController::willDisplay()
+{
+    InspectorInstrumentation::willDisplay(m_page);
+}
+// Playwright end
+
 void InspectorController::willComposite(Frame& frame)
 {
     InspectorInstrumentation::willComposite(frame);
@@ -515,4 +528,24 @@ 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 bca5ead33d04e3b1f4d67cd335242334e93892ca..b04d073a4bacc021c3269b1efd12d683969fcbc4 100644
--- a/Source/WebCore/inspector/InspectorController.h
+++ b/Source/WebCore/inspector/InspectorController.h
@@ -98,9 +98,16 @@ public:
 
     WEBCORE_EXPORT void setIndicating(bool);
 
+// Playwright begin
+    WEBCORE_EXPORT void willDisplay();
+// Playwright end
     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);
@@ -150,6 +157,7 @@ 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 ed763c11eb95646f63ecf8dda708ab88414f3290..a60cf099c1bed2646bfcff1bad8a59fff770dc50 100644
--- a/Source/WebCore/inspector/InspectorInstrumentation.cpp
+++ b/Source/WebCore/inspector/InspectorInstrumentation.cpp
@@ -80,6 +80,12 @@
 #include <JavaScriptCore/ScriptCallStack.h>
 #include <wtf/StdLibExtras.h>
 
+// Playwright begin
+#if PLATFORM(WPE) || PLATFORM(WIN)
+#include "InspectorScreencastAgent.h"
+#endif
+// Playwright end
+
 #if ENABLE(WEBGPU)
 #include "WebGPUSwapChain.h"
 #endif
@@ -501,6 +507,19 @@ void InspectorInstrumentation::didLayoutImpl(InstrumentingAgents& instrumentingA
         pageAgent->didLayout();
 }
 
+// Playwright begin
+void InspectorInstrumentation::willDisplayImpl(InstrumentingAgents& instrumentingAgents)
+{
+#if PLATFORM(WPE) || PLATFORM(WIN)
+
+    if (auto* screencastAgent = instrumentingAgents.enabledInspectorScreencastAgent())
+        screencastAgent->willDisplay();
+#else
+    UNUSED_PARAM(instrumentingAgents);
+#endif
+}
+// Playwright end
+
 void InspectorInstrumentation::willCompositeImpl(InstrumentingAgents& instrumentingAgents, Frame& frame)
 {
     if (auto* timelineAgent = instrumentingAgents.trackingTimelineAgent())
@@ -627,6 +646,12 @@ 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.enabledPageRuntimeAgent())
+        pageRuntimeAgent->didReceiveMainResourceError(frame);
+}
+
 void InspectorInstrumentation::willLoadXHRSynchronouslyImpl(InstrumentingAgents& instrumentingAgents)
 {
     if (auto* networkAgent = instrumentingAgents.enabledNetworkAgent())
@@ -659,20 +684,17 @@ void InspectorInstrumentation::didReceiveScriptResponseImpl(InstrumentingAgents&
 
 void InspectorInstrumentation::domContentLoadedEventFiredImpl(InstrumentingAgents& instrumentingAgents, Frame& frame)
 {
-    if (!frame.isMainFrame())
-        return;
-
     if (auto* pageAgent = instrumentingAgents.enabledPageAgent())
-        pageAgent->domContentEventFired();
+        pageAgent->domContentEventFired(frame);
 }
 
 void InspectorInstrumentation::loadEventFiredImpl(InstrumentingAgents& instrumentingAgents, Frame* frame)
 {
-    if (!frame || !frame->isMainFrame())
+    if (!frame)
         return;
 
     if (auto* pageAgent = instrumentingAgents.enabledPageAgent())
-        pageAgent->loadEventFired();
+        pageAgent->loadEventFired(*frame);
 }
 
 void InspectorInstrumentation::frameDetachedFromParentImpl(InstrumentingAgents& instrumentingAgents, Frame& frame)
@@ -750,12 +772,6 @@ void InspectorInstrumentation::frameDocumentUpdatedImpl(InstrumentingAgents& ins
         pageDOMDebuggerAgent->frameDocumentUpdated(frame);
 }
 
-void InspectorInstrumentation::loaderDetachedFromFrameImpl(InstrumentingAgents& instrumentingAgents, DocumentLoader& loader)
-{
-    if (auto* inspectorPageAgent = instrumentingAgents.enabledPageAgent())
-        inspectorPageAgent->loaderDetachedFromFrame(loader);
-}
-
 void InspectorInstrumentation::frameStartedLoadingImpl(InstrumentingAgents& instrumentingAgents, Frame& frame)
 {
     if (frame.isMainFrame()) {
@@ -792,6 +808,12 @@ void InspectorInstrumentation::frameClearedScheduledNavigationImpl(Instrumenting
         inspectorPageAgent->frameClearedScheduledNavigation(frame);
 }
 
+void InspectorInstrumentation::didNavigateWithinPageImpl(InstrumentingAgents& instrumentingAgents, Frame& frame)
+{
+    if (InspectorPageAgent* inspectorPageAgent = instrumentingAgents.enabledPageAgent())
+        inspectorPageAgent->didNavigateWithinPage(frame);
+}
+
 #if ENABLE(DARK_MODE_CSS) || HAVE(OS_DARK_MODE_SUPPORT)
 void InspectorInstrumentation::defaultAppearanceDidChangeImpl(InstrumentingAgents& instrumentingAgents, bool useDarkAppearance)
 {
@@ -1302,6 +1324,43 @@ void InspectorInstrumentation::renderLayerDestroyedImpl(InstrumentingAgents& ins
         layerTreeAgent->renderLayerDestroyed(renderLayer);
 }
 
+void InspectorInstrumentation::runOpenPanelImpl(InstrumentingAgents& instrumentingAgents, HTMLInputElement* element, bool* intercept)
+{
+    if (InspectorPageAgent* pageAgent = instrumentingAgents.enabledPageAgent())
+        pageAgent->runOpenPanel(element, intercept);
+}
+
+void InspectorInstrumentation::frameAttachedImpl(InstrumentingAgents& instrumentingAgents, Frame& frame) {
+    if (InspectorPageAgent* pageAgent = instrumentingAgents.enabledPageAgent())
+        pageAgent->frameAttached(frame);
+}
+
+bool InspectorInstrumentation::shouldBypassCSPImpl(InstrumentingAgents& instrumentingAgents)
+{
+    if (InspectorPageAgent* pageAgent = instrumentingAgents.enabledPageAgent())
+        return pageAgent->shouldBypassCSP();
+    return false;
+}
+
+void InspectorInstrumentation::willCheckNewWindowPolicyImpl(InstrumentingAgents& instrumentingAgents, const URL& url)
+{
+    if (InspectorPageAgent* pageAgent = instrumentingAgents.enabledPageAgent())
+        pageAgent->willCheckNewWindowPolicy(url);
+}
+
+void InspectorInstrumentation::didCheckNewWindowPolicyImpl(InstrumentingAgents& instrumentingAgents, bool allowed)
+{
+    if (InspectorPageAgent* pageAgent = instrumentingAgents.enabledPageAgent())
+        pageAgent->didCheckNewWindowPolicy(allowed);
+}
+
+bool InspectorInstrumentation::interceptRequestImpl(InstrumentingAgents& instrumentingAgents, ResourceLoader& loader, Function<void(bool handled)>&& handler)
+{
+    if (InspectorNetworkAgent* networkAgent = instrumentingAgents.enabledNetworkAgent())
+        return networkAgent->interceptRequest(loader, WTFMove(handler));
+    return false;
+}
+
 InstrumentingAgents& InspectorInstrumentation::instrumentingAgentsForWorkerGlobalScope(WorkerGlobalScope& workerGlobalScope)
 {
     return workerGlobalScope.inspectorController().m_instrumentingAgents;
@@ -1313,6 +1372,13 @@ InstrumentingAgents& InspectorInstrumentation::instrumentingAgentsForPage(Page&
     return page.inspectorController().m_instrumentingAgents.get();
 }
 
+void InspectorInstrumentation::maybeOverrideDefaultObjectInclusion(Page& page, AccessibilityObjectInclusion& inclusion) {
+    if (InspectorPageAgent* pageAgent = InspectorInstrumentation::instrumentingAgentsForPage(page).enabledPageAgent()) {
+        if (pageAgent->doingAccessibilitySnapshot())
+            inclusion = AccessibilityObjectInclusion::DefaultBehavior;
+    }
+}
+
 InstrumentingAgents* InspectorInstrumentation::instrumentingAgentsForContext(ScriptExecutionContext& context)
 {
     if (is<Document>(context))
diff --git a/Source/WebCore/inspector/InspectorInstrumentation.h b/Source/WebCore/inspector/InspectorInstrumentation.h
index c7b66ba1155d91b3c5e0e312e14bd2fe73286d25..d046c6143fa7ea720540ca41fe586044a5b0461c 100644
--- a/Source/WebCore/inspector/InspectorInstrumentation.h
+++ b/Source/WebCore/inspector/InspectorInstrumentation.h
@@ -31,6 +31,7 @@
 
 #pragma once
 
+#include "AccessibilityObjectInterface.h"
 #include "CSSSelector.h"
 #include "CallTracerTypes.h"
 #include "CanvasBase.h"
@@ -45,12 +46,14 @@
 #include "HitTestResult.h"
 #include "InspectorInstrumentationPublic.h"
 #include "Page.h"
+#include "ResourceLoader.h"
 #include "StorageArea.h"
 #include "WebAnimation.h"
 #include "WorkerInspectorProxy.h"
 #include <JavaScriptCore/ConsoleMessage.h>
 #include <initializer_list>
 #include <wtf/CompletionHandler.h>
+#include <wtf/Function.h>
 #include <wtf/MemoryPressureHandler.h>
 #include <wtf/RefPtr.h>
 
@@ -78,6 +81,7 @@ class DOMWrapperWorld;
 class Document;
 class DocumentLoader;
 class EventListener;
+class HTMLInputElement;
 class HTTPHeaderMap;
 class InspectorTimelineAgent;
 class InstrumentingAgents;
@@ -181,6 +185,9 @@ public:
     static void willLayout(Frame&);
     static void didLayout(Frame&, RenderObject&);
     static void didScroll(Page&);
+// Playwright begin
+    static void willDisplay(Page&);
+// Playwright end
     static void willComposite(Frame&);
     static void didComposite(Frame&);
     static void willPaint(RenderObject&);
@@ -198,6 +205,7 @@ 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&);
@@ -224,11 +232,11 @@ 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&);
 #if ENABLE(DARK_MODE_CSS) || HAVE(OS_DARK_MODE_SUPPORT)
     static void defaultAppearanceDidChange(Page&, bool useDarkAppearance);
 #endif
@@ -321,6 +329,13 @@ 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 void willCheckNewWindowPolicy(Frame&, const URL&);
+    static void didCheckNewWindowPolicy(Frame&, bool allowed);
+    static bool interceptRequest(ResourceLoader&, Function<void(bool handled)>&&);
+
     static void frontendCreated();
     static void frontendDeleted();
     static bool hasFrontends() { return InspectorInstrumentationPublic::hasFrontends(); }
@@ -336,6 +351,8 @@ public:
     static void registerInstrumentingAgents(InstrumentingAgents&);
     static void unregisterInstrumentingAgents(InstrumentingAgents&);
 
+    static void maybeOverrideDefaultObjectInclusion(Page&, AccessibilityObjectInclusion&);
+
 private:
     static void didClearWindowObjectInWorldImpl(InstrumentingAgents&, Frame&, DOMWrapperWorld&);
     static bool isDebuggerPausedImpl(InstrumentingAgents&);
@@ -403,6 +420,9 @@ private:
     static void willLayoutImpl(InstrumentingAgents&, Frame&);
     static void didLayoutImpl(InstrumentingAgents&, RenderObject&);
     static void didScrollImpl(InstrumentingAgents&);
+// Playwright begin
+    static void willDisplayImpl(InstrumentingAgents&);
+// Playwright end
     static void willCompositeImpl(InstrumentingAgents&, Frame&);
     static void didCompositeImpl(InstrumentingAgents&);
     static void willPaintImpl(InstrumentingAgents&, RenderObject&);
@@ -422,6 +442,7 @@ 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);
@@ -432,11 +453,11 @@ 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&);
 #if ENABLE(DARK_MODE_CSS) || HAVE(OS_DARK_MODE_SUPPORT)
     static void defaultAppearanceDidChangeImpl(InstrumentingAgents&, bool useDarkAppearance);
 #endif
@@ -525,6 +546,13 @@ 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 void willCheckNewWindowPolicyImpl(InstrumentingAgents&, const URL&);
+    static void didCheckNewWindowPolicyImpl(InstrumentingAgents&, bool allowed);
+    static bool interceptRequestImpl(InstrumentingAgents&, ResourceLoader&, Function<void(bool handled)>&&);
+
     static InstrumentingAgents& instrumentingAgentsForPage(Page&);
     static InstrumentingAgents& instrumentingAgentsForWorkerGlobalScope(WorkerGlobalScope&);
 
@@ -974,6 +1002,14 @@ inline void InspectorInstrumentation::didScroll(Page& page)
     didScrollImpl(instrumentingAgentsForPage(page));
 }
 
+// Playwright begin
+inline void InspectorInstrumentation::willDisplay(Page& page)
+{
+    FAST_RETURN_IF_NO_FRONTENDS(void());
+    willDisplayImpl(instrumentingAgentsForPage(page));
+}
+// Playwright end
+
 inline void InspectorInstrumentation::willComposite(Frame& frame)
 {
     FAST_RETURN_IF_NO_FRONTENDS(void());
@@ -1113,6 +1149,13 @@ 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);
@@ -1208,13 +1251,6 @@ 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());
@@ -1243,6 +1279,13 @@ 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);
+}
+
 #if ENABLE(DARK_MODE_CSS) || HAVE(OS_DARK_MODE_SUPPORT)
 inline void InspectorInstrumentation::defaultAppearanceDidChange(Page& page, bool useDarkAppearance)
 {
@@ -1702,6 +1745,50 @@ 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 void InspectorInstrumentation::willCheckNewWindowPolicy(Frame& frame, const URL& url)
+{
+    FAST_RETURN_IF_NO_FRONTENDS(void());
+    if (InstrumentingAgents* instrumentingAgents = instrumentingAgentsForFrame(frame))
+        willCheckNewWindowPolicyImpl(*instrumentingAgents, url);
+}
+
+inline void InspectorInstrumentation::didCheckNewWindowPolicy(Frame& frame, bool allowed)
+{
+    FAST_RETURN_IF_NO_FRONTENDS(void());
+    if (InstrumentingAgents* instrumentingAgents = instrumentingAgentsForFrame(frame))
+        didCheckNewWindowPolicyImpl(*instrumentingAgents, allowed);
+}
+
+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/InstrumentingAgents.h b/Source/WebCore/inspector/InstrumentingAgents.h
index 829dc952b8ce80e15ec9f4f343587008b5a41d2e..b94fef468607453d0c87337678d1b68046d3b963 100644
--- a/Source/WebCore/inspector/InstrumentingAgents.h
+++ b/Source/WebCore/inspector/InstrumentingAgents.h
@@ -56,6 +56,7 @@ class InspectorLayerTreeAgent;
 class InspectorMemoryAgent;
 class InspectorNetworkAgent;
 class InspectorPageAgent;
+class InspectorScreencastAgent;
 class InspectorTimelineAgent;
 class InspectorWorkerAgent;
 class PageDOMDebuggerAgent;
@@ -84,6 +85,7 @@ class WebDebuggerAgent;
 #define DEFINE_INSPECTOR_AGENT_Network(macro, Getter, Setter) DEFINE_INSPECTOR_AGENT(macro, InspectorNetworkAgent, NetworkAgent, Getter, Setter)
 #define DEFINE_INSPECTOR_AGENT_Page(macro, Getter, Setter) DEFINE_INSPECTOR_AGENT(macro, InspectorPageAgent, PageAgent, Getter, Setter)
 #define DEFINE_INSPECTOR_AGENT_Runtime_Page(macro, Getter, Setter) DEFINE_INSPECTOR_AGENT(macro, PageRuntimeAgent, PageRuntimeAgent, Getter, Setter)
+#define DEFINE_INSPECTOR_AGENT_Screencast(macro, Getter, Setter) DEFINE_INSPECTOR_AGENT(macro, InspectorScreencastAgent, InspectorScreencastAgent, Getter, Setter)
 #define DEFINE_INSPECTOR_AGENT_ScriptProfiler(macro, Getter, Setter) DEFINE_INSPECTOR_AGENT(macro, Inspector::InspectorScriptProfilerAgent, ScriptProfilerAgent, Getter, Setter)
 #define DEFINE_INSPECTOR_AGENT_Timeline(macro, Getter, Setter) DEFINE_INSPECTOR_AGENT(macro, InspectorTimelineAgent, TimelineAgent, Getter, Setter)
 #define DEFINE_INSPECTOR_AGENT_Worker(macro, Getter, Setter) DEFINE_INSPECTOR_AGENT(macro, InspectorWorkerAgent, WorkerAgent, Getter, Setter)
@@ -125,6 +127,7 @@ class WebDebuggerAgent;
     DEFINE_ENABLED_INSPECTOR_AGENT(macro, DOMDebugger_Page) \
     DEFINE_ENABLED_INSPECTOR_AGENT(macro, DOMStorage) \
     DEFINE_ENABLED_INSPECTOR_AGENT(macro, Heap_Page) \
+    DEFINE_ENABLED_INSPECTOR_AGENT(macro, Screencast) \
     DEFINE_ENABLED_INSPECTOR_AGENT(macro, LayerTree) \
     DEFINE_ENABLED_INSPECTOR_AGENT(macro, Memory) \
     DEFINE_ENABLED_INSPECTOR_AGENT(macro, Network) \
diff --git a/Source/WebCore/inspector/agents/InspectorDOMAgent.cpp b/Source/WebCore/inspector/agents/InspectorDOMAgent.cpp
index 8acc1f6dba71a7d3421f135112bcf8bbc70c4128..5645f2a7a61e26f3534aeb6dd281260f50db677b 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);
@@ -1337,16 +1359,7 @@ 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;
 
@@ -1494,18 +1507,147 @@ 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.enabledPageAgent();
+    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;
+    }
+    m_inspectedPage.updateRendering();
+    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.
+    m_inspectedPage.updateRendering();
+
+    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)
@@ -2670,7 +2812,7 @@ 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())
@@ -2679,12 +2821,16 @@ 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)
@@ -2705,4 +2851,46 @@ 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 7e6d3f68d3d60caf3d3a01acc380a2605f42d6e3..426716243b178543bc96799401a0a1ce6d6db26a 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.
@@ -131,7 +133,7 @@ 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;
 #if PLATFORM(IOS_FAMILY)
     void setInspectModeEnabled(ErrorString&, bool enabled, const JSON::Object* highlightConfig) override;
@@ -154,6 +156,10 @@ 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&);
@@ -191,7 +197,7 @@ 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*);
@@ -202,12 +208,15 @@ 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();
@@ -234,9 +243,8 @@ 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 ddbb5d5347f3beabe3cfab201d6838c896d21e39..25f1798cad5a4ef135a27d3bd5146798d1077a13 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 2cf4988f13222be5418b0a23116b8dc96b1f83f7..b76642505aaeece2e8159486ac82e52ffb535dc5 100644
--- a/Source/WebCore/inspector/agents/InspectorNetworkAgent.cpp
+++ b/Source/WebCore/inspector/agents/InspectorNetworkAgent.cpp
@@ -43,6 +43,7 @@
 #include "DocumentLoader.h"
 #include "DocumentThreadableLoader.h"
 #include "Frame.h"
+#include "FormData.h"
 #include "FrameLoader.h"
 #include "HTTPHeaderMap.h"
 #include "HTTPHeaderNames.h"
@@ -55,6 +56,7 @@
 #include "MIMETypeRegistry.h"
 #include "MemoryCache.h"
 #include "NetworkResourcesData.h"
+#include "NetworkStateNotifier.h"
 #include "Page.h"
 #include "PlatformStrategies.h"
 #include "ProgressTracker.h"
@@ -483,8 +485,14 @@ static InspectorPageAgent::ResourceType resourceTypeForLoadType(InspectorInstrum
 
 void InspectorNetworkAgent::willSendRequest(unsigned long identifier, DocumentLoader* loader, ResourceRequest& request, const ResourceResponse& redirectResponse)
 {
-    auto* cachedResource = loader ? InspectorPageAgent::cachedResource(loader->frame(), request.url()) : nullptr;
-    willSendRequest(identifier, loader, request, redirectResponse, resourceTypeForCachedResource(cachedResource));
+    InspectorPageAgent::ResourceType resourceType;
+    if (request.initiatorIdentifier() == initiatorIdentifierForEventSource()) {
+      resourceType = InspectorPageAgent::EventSource;
+    } else {
+      auto* cachedResource = loader ? InspectorPageAgent::cachedResource(loader->frame(), request.url()) : nullptr;
+      resourceType = resourceTypeForCachedResource(cachedResource);
+    }
+    willSendRequest(identifier, loader, request, redirectResponse, resourceType);
 }
 
 void InspectorNetworkAgent::willSendRequestOfType(unsigned long identifier, DocumentLoader* loader, ResourceRequest& request, InspectorInstrumentation::LoadType loadType)
@@ -840,6 +848,7 @@ void InspectorNetworkAgent::disable(ErrorString&)
     m_resourcesData->clear();
     m_extraRequestHeaders.clear();
 
+    continuePendingRequests();
     continuePendingResponses();
 
     setResourceCachingDisabled(false);
@@ -863,6 +872,16 @@ 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())
@@ -1019,17 +1038,15 @@ 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)
@@ -1111,19 +1128,133 @@ 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());
+        if (response.isRedirection()) {
+            loader->setRequest(loader->request().redirectedRequest(response, false));
+            pendingRequest->m_callback(false);
+        } else {
+            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;
@@ -1151,20 +1282,26 @@ 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/")
@@ -1205,6 +1342,12 @@ Optional<String> InspectorNetworkAgent::textContentForCachedResource(CachedResou
     return WTF::nullopt;
 }
 
+// static
+String InspectorNetworkAgent::initiatorIdentifierForEventSource()
+{
+    return "InspectorNetworkAgent: eventSource"_s;
+}
+
 bool InspectorNetworkAgent::cachedResourceContent(CachedResource& resource, String* result, bool* base64Encoded)
 {
     ASSERT(result);
diff --git a/Source/WebCore/inspector/agents/InspectorNetworkAgent.h b/Source/WebCore/inspector/agents/InspectorNetworkAgent.h
index bfd131e9b5856c84da7724805e71397b7c7486a9..8f5fe68c21fac2780b0d2aff4f0e63cd8b2858b4 100644
--- a/Source/WebCore/inspector/agents/InspectorNetworkAgent.h
+++ b/Source/WebCore/inspector/agents/InspectorNetworkAgent.h
@@ -73,6 +73,7 @@ public:
     static Ref<TextResourceDecoder> createTextDecoder(const String& mimeType, const String& textEncodingName);
     static Optional<String> textContentForCachedResource(CachedResource&);
     static bool cachedResourceContent(CachedResource&, String* result, bool* base64Encoded);
+    static String initiatorIdentifierForEventSource();
 
     // InspectorAgentBase
     void didCreateFrontendAndBackend(Inspector::FrontendRouter*, Inspector::BackendDispatcher*) final;
@@ -87,11 +88,13 @@ 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();
@@ -121,6 +124,7 @@ 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>>&);
@@ -141,6 +145,7 @@ 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 +196,15 @@ 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 +228,7 @@ 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 +237,7 @@ 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 539e8105b66e7b2a6a05571a1e1c8cd6bdf27c90..45489cd5e978ac70be8fb33bb3e137ab5eff2d11 100644
--- a/Source/WebCore/inspector/agents/InspectorPageAgent.cpp
+++ b/Source/WebCore/inspector/agents/InspectorPageAgent.cpp
@@ -32,19 +32,27 @@
 #include "config.h"
 #include "InspectorPageAgent.h"
 
+#include "AXObjectCache.h"
+#include "BackForwardController.h"
 #include "CachedResource.h"
 #include "CachedResourceLoader.h"
 #include "Cookie.h"
 #include "CookieJar.h"
+#include "CustomHeaderFields.h"
+#include "CSSAnimationController.h"
 #include "DOMWrapperWorld.h"
 #include "Document.h"
+#include "DocumentTimeline.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"
@@ -55,19 +63,30 @@
 #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 "SVGDocumentExtensions.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 <wtf/DateMath.h>
 #include <wtf/ListHashSet.h>
+#include <wtf/MainThread.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>
@@ -80,11 +99,15 @@
 #include "LegacyWebArchive.h"
 #endif
 
-
 namespace WebCore {
 
 using namespace Inspector;
 
+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) {
@@ -236,6 +259,8 @@ Inspector::Protocol::Page::ResourceType InspectorPageAgent::resourceTypeJSON(Ins
         return Inspector::Protocol::Page::ResourceType::Beacon;
     case WebSocketResource:
         return Inspector::Protocol::Page::ResourceType::WebSocket;
+    case EventSource:
+        return Inspector::Protocol::Page::ResourceType::EventSource;
     case OtherResource:
         return Inspector::Protocol::Page::ResourceType::Other;
 #if ENABLE(APPLICATION_MANIFEST)
@@ -325,6 +350,7 @@ 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)
 {
@@ -358,11 +384,20 @@ void InspectorPageAgent::enable(ErrorString& errorString)
 #if ENABLE(DARK_MODE_CSS) || 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.setEnabledPageAgent(nullptr);
+    m_interceptFileChooserDialog = false;
+    m_bypassCSP = false;
 
     ErrorString unused;
     setShowPaintRects(unused, false);
@@ -412,6 +447,18 @@ void InspectorPageAgent::reload(ErrorString&, const bool* optionalReloadFromOrig
     m_inspectedPage.mainFrame().loader().reload(reloadOptions);
 }
 
+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&, const String& url)
 {
     UserGestureIndicator indicator { ProcessingUserGesture };
@@ -791,15 +838,16 @@ 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)
@@ -807,13 +855,23 @@ void InspectorPageAgent::frameNavigated(Frame& frame)
     m_frontendDispatcher->frameNavigated(buildObjectForFrame(&frame));
 }
 
+String InspectorPageAgent::makeFrameID(ProcessIdentifier processID,  FrameIdentifier frameID)
+{
+    return makeString(processID.toUInt64(), ".", frameID.toUInt64());
+}
+
+static String globalIDForFrame(Frame& frame)
+{
+    return InspectorPageAgent::makeFrameID(Process::identifier(), *frame.loader().client().frameID());
+}
+
 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)
@@ -825,20 +883,18 @@ 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)
@@ -849,11 +905,6 @@ 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));
@@ -874,6 +925,12 @@ 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);
+}
+
 #if ENABLE(DARK_MODE_CSS) || HAVE(OS_DARK_MODE_SUPPORT)
 void InspectorPageAgent::defaultAppearanceDidChange(bool useDarkAppearance)
 {
@@ -933,6 +990,48 @@ 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;
+}
+
+void InspectorPageAgent::willCheckNewWindowPolicy(const URL& url)
+{
+    m_frontendDispatcher->willRequestOpenWindow(url.string());
+}
+
+void InspectorPageAgent::didCheckNewWindowPolicy(bool allowed)
+{
+    m_frontendDispatcher->didRequestOpenWindow(allowed);
+}
+
 Ref<Inspector::Protocol::Page::Frame> InspectorPageAgent::buildObjectForFrame(Frame* frame)
 {
     ASSERT_ARG(frame, frame);
@@ -1073,6 +1172,29 @@ 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
+}
+
+
 #if ENABLE(WEB_ARCHIVE) && USE(CF)
 void InspectorPageAgent::archive(ErrorString& errorString, String* data)
 {
@@ -1087,4 +1209,578 @@ 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.persistentDOMAgent();
+        ASSERT(domAgent);
+        node = domAgent->nodeForObjectId(*objectId);
+        if (!node) {
+            errorString = "No Node for objectId"_s;
+            return;
+        }
+    }
+
+    m_doingAccessibilitySnapshot = true;
+    out_axNode = snapshotForAXObject(makeRefPtr(axObject), node);
+    m_doingAccessibilitySnapshot = false;
+}
+
+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);
+}
+
+void InspectorPageAgent::setOrientationOverride(Inspector::ErrorString& errorString, const int* angle)
+{
+#if ENABLE(ORIENTATION_EVENTS)
+    UNUSED_PARAM(errorString);
+    Optional<int> orientation;
+    if (angle)
+        orientation = *angle;
+    m_inspectedPage.setOverrideOrientation(orientation);
+#else
+    errorString = "Orientation events are disabled in this build";
+#endif
+}
+
+void InspectorPageAgent::setActivityPaused(Inspector::ErrorString&, bool paused)
+{
+    setMainThreadCallbacksPaused(paused);
+    bool webAnimationsCSSIntegrationEnabled = RuntimeEnabledFeatures::sharedFeatures().webAnimationsCSSIntegrationEnabled();
+    for (Frame* frame = &m_inspectedPage.mainFrame(); frame; frame = frame->tree().traverseNext()) {
+        ASSERT(frame->document());
+        auto& document = *frame->document();
+        if (paused) {
+            document.suspendScriptedAnimationControllerCallbacks();
+            document.suspendActiveDOMObjects(ReasonForSuspension::JavaScriptDebuggerPaused);
+            if (webAnimationsCSSIntegrationEnabled) {
+                if (auto* timeline = document.existingTimeline())
+                    timeline->suspendAnimations();
+            }
+            if (document.svgExtensions())
+                document.accessSVGExtensions().pauseAnimations();
+        } else {
+            document.resumeActiveDOMObjects(ReasonForSuspension::JavaScriptDebuggerPaused);
+            document.resumeScriptedAnimationControllerCallbacks();
+            if (webAnimationsCSSIntegrationEnabled) {
+                if (auto* timeline = document.existingTimeline())
+                    timeline->resumeAnimations();
+            }
+            if (document.svgExtensions())
+                document.accessSVGExtensions().unpauseAnimations();
+        }
+    }
+    if (!webAnimationsCSSIntegrationEnabled) {
+      if (paused)
+        m_inspectedPage.mainFrame().legacyAnimation().suspendAnimations();
+      else
+        m_inspectedPage.mainFrame().legacyAnimation().resumeAnimations();
+    }
+}
+
 } // namespace WebCore
diff --git a/Source/WebCore/inspector/agents/InspectorPageAgent.h b/Source/WebCore/inspector/agents/InspectorPageAgent.h
index 3bcd0487cfc8766baa01c7804173a15747b47b2d..3b5c230d7e00b9d7e248be8730ab22ab1d4fe40b 100644
--- a/Source/WebCore/inspector/agents/InspectorPageAgent.h
+++ b/Source/WebCore/inspector/agents/InspectorPageAgent.h
@@ -34,17 +34,23 @@
 #include "CachedResource.h"
 #include "InspectorWebAgentBase.h"
 #include "LayoutRect.h"
+#include "ProcessIdentifier.h"
 #include <JavaScriptCore/InspectorBackendDispatchers.h>
 #include <JavaScriptCore/InspectorFrontendDispatchers.h>
 #include <wtf/HashMap.h>
 #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;
@@ -71,12 +77,14 @@ public:
         PingResource,
         BeaconResource,
         WebSocketResource,
+        EventSource,
 #if ENABLE(APPLICATION_MANIFEST)
         ApplicationManifestResource,
 #endif
         OtherResource,
     };
 
+    WEBCORE_EXPORT static String makeFrameID(ProcessIdentifier processID,  FrameIdentifier frameID);
     static bool sharedBufferContent(RefPtr<SharedBuffer>&&, const String& textEncodingName, bool withBase64Encode, String* result);
     static Vector<CachedResource*> cachedResourcesForFrame(Frame*);
     static void resourceContent(ErrorString&, Frame*, const URL&, String* result, bool* base64Encoded);
@@ -97,6 +105,8 @@ public:
     void enable(ErrorString&) override;
     void disable(ErrorString&) override;
     void reload(ErrorString&, const bool* optionalReloadFromOrigin, const bool* optionalRevalidateAllResources) override;
+    void goBack(ErrorString&) override;
+    void goForward(ErrorString&) override;
     void navigate(ErrorString&, const String& url) override;
     void overrideUserAgent(ErrorString&, const String* value) override;
     void overrideSetting(ErrorString&, const String& setting, const bool* value) override;
@@ -116,22 +126,35 @@ public:
 #if ENABLE(DARK_MODE_CSS) || HAVE(OS_DARK_MODE_SUPPORT)
     void setForcedAppearance(ErrorString&, const String&) override;
 #endif
+    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;
 #if ENABLE(WEB_ARCHIVE) && USE(CF)
     void archive(ErrorString&, String* data) override;
 #endif
 
+    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;
+    void setOrientationOverride(Inspector::ErrorString&, const int* angle) override;
+    void setActivityPaused(Inspector::ErrorString&, bool) 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&);
 #if ENABLE(DARK_MODE_CSS) || HAVE(OS_DARK_MODE_SUPPORT)
     void defaultAppearanceDidChange(bool useDarkAppearance);
 #endif
@@ -142,6 +165,12 @@ public:
     void didLayout();
     void didScroll();
     void didRecalculateStyle();
+    void runOpenPanel(HTMLInputElement* element, bool* intercept);
+    void frameAttached(Frame&);
+    bool shouldBypassCSP();
+    void willCheckNewWindowPolicy(const URL&);
+    void didCheckNewWindowPolicy(bool allowed);
+    bool doingAccessibilitySnapshot() const { return m_doingAccessibilitySnapshot; };
 
     Frame* frameForId(const String& frameId);
     WEBCORE_EXPORT String frameId(Frame*);
@@ -150,6 +179,7 @@ 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);
@@ -161,17 +191,19 @@ 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_bootstrapScript;
     bool m_isFirstLayoutAfterOnLoad { false };
     bool m_showPaintRects { false };
+    bool m_interceptFileChooserDialog { false };
+    bool m_bypassCSP { false };
+    bool m_doingAccessibilitySnapshot { false };
 };
 
 } // namespace WebCore
diff --git a/Source/WebCore/inspector/agents/InspectorScreencastAgent.cpp b/Source/WebCore/inspector/agents/InspectorScreencastAgent.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..da7187ccf379eef1346aae10a0f34361dffb1499
--- /dev/null
+++ b/Source/WebCore/inspector/agents/InspectorScreencastAgent.cpp
@@ -0,0 +1,160 @@
+/*
+ * 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 "InspectorScreencastAgent.h"
+
+#if PLATFORM(WPE) || PLATFORM(WIN)
+
+#include "Page.h"
+#include "FrameSnapshotting.h"
+#include "ImageBuffer.h"
+#include <JavaScriptCore/InspectorFrontendDispatchers.h>
+#include <JavaScriptCore/InspectorFrontendRouter.h>
+
+namespace WebCore {
+
+using namespace Inspector;
+
+InspectorScreencastAgent::InspectorScreencastAgent(PageAgentContext& context)
+    : InspectorAgentBase("Screencast"_s, context)
+    , m_frontendDispatcher(makeUnique<ScreencastFrontendDispatcher>(context.frontendRouter))
+    , m_backendDispatcher(ScreencastBackendDispatcher::create(context.backendDispatcher, this))
+    , m_inspectedPage(context.inspectedPage)
+{
+}
+
+InspectorScreencastAgent::~InspectorScreencastAgent()
+{
+}
+
+void InspectorScreencastAgent::didCreateFrontendAndBackend(FrontendRouter*, BackendDispatcher*)
+{
+}
+
+void InspectorScreencastAgent::willDestroyFrontendAndBackend(DisconnectReason)
+{
+    ErrorString errorString;
+    stop(errorString);
+}
+
+void InspectorScreencastAgent::start(Inspector::ErrorString& errorString, const String& format, const int* quality)
+{
+    if (isEnabled())
+      return;
+
+    if (format == "jpeg") {
+        m_format = "image/jpeg";
+    } else if (format == "png") {
+        m_format = "image/png";
+    } else {
+        errorString = "Unsupported format."_s;
+        return;
+    }
+
+    if (quality && (*quality < 0 || *quality >100)) {
+        errorString = "Unsupported quality."_s;
+        return;
+    }
+
+    if (quality)
+        m_quality = *quality;
+    m_instrumentingAgents.setEnabledInspectorScreencastAgent(this);
+}
+
+void InspectorScreencastAgent::stop(Inspector::ErrorString&)
+{
+    if (!isEnabled())
+      return;
+
+    m_instrumentingAgents.setEnabledInspectorScreencastAgent(nullptr);
+    m_inflightFrames = 0;
+    m_quality = WTF::nullopt;
+}
+
+void InspectorScreencastAgent::frameAck(Inspector::ErrorString& errorString)
+{
+    if (!m_inflightFrames) {
+        errorString = "No inflight frames to ack"_s;
+        return;
+    }
+
+    --m_inflightFrames;
+}
+
+void InspectorScreencastAgent::startVideoRecording(Inspector::ErrorString& errorString, const String&, int, int, const double*)
+{
+    errorString = "Not implemented."_s;
+}
+
+void InspectorScreencastAgent::stopVideoRecording(Ref<StopVideoRecordingCallback>&& callback)
+{
+    callback->sendFailure("Not implemented."_s);
+}
+
+bool InspectorScreencastAgent::isEnabled() const
+{
+    return m_instrumentingAgents.enabledInspectorScreencastAgent();
+}
+
+void InspectorScreencastAgent::willDisplay()
+{
+    if (!isEnabled())
+        return;
+
+    if (m_inflightFrames > 2)
+        return;
+
+    String snapshot = takeSnapshot();
+    if (snapshot.isEmpty())
+        return;
+
+    ++m_inflightFrames;
+    m_frontendDispatcher->frame(snapshot);
+}
+
+String InspectorScreencastAgent::takeSnapshot()
+{
+    SnapshotOptions options = SnapshotOptionsNone;
+    options |= SnapshotOptionsInViewCoordinates;
+    IntSize size = m_inspectedPage.mainFrame().view()->visibleSize();
+    fprintf(stderr, "view().visibleSize() = %s\n", size.toJSONString().ascii().data());
+    IntRect rectangle({0, 0}, size);
+    std::unique_ptr<ImageBuffer> snapshot = snapshotFrameRect(m_inspectedPage.mainFrame(), rectangle, options);
+
+    if (!snapshot)
+        return String();
+
+    Optional<double> quality;
+    if (m_quality)
+        quality = *m_quality / 100.0;
+
+    Vector<uint8_t> data = snapshot->toData(m_format, quality);
+    return base64Encode(data);
+}
+
+} // namespace WebCore
+
+#endif  // PLATFORM(WPE) || PLATFORM(WIN)
diff --git a/Source/WebCore/inspector/agents/InspectorScreencastAgent.h b/Source/WebCore/inspector/agents/InspectorScreencastAgent.h
new file mode 100644
index 0000000000000000000000000000000000000000..f725430dd38ec528396b8edae12a9a941bb0b835
--- /dev/null
+++ b/Source/WebCore/inspector/agents/InspectorScreencastAgent.h
@@ -0,0 +1,81 @@
+/*
+ * 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 PLATFORM(WPE) || PLATFORM(WIN)
+
+#include "InspectorWebAgentBase.h"
+#include <JavaScriptCore/InspectorBackendDispatchers.h>
+#include <JavaScriptCore/InspectorFrontendDispatchers.h>
+
+#include <wtf/Forward.h>
+#include <wtf/Noncopyable.h>
+#include <wtf/WeakPtr.h>
+
+namespace Inspector {
+class BackendDispatcher;
+class FrontendChannel;
+class FrontendRouter;
+class ScreencastFrontendDispatcher;
+}
+
+namespace WebCore {
+
+class Page;
+
+class InspectorScreencastAgent : public InspectorAgentBase, public Inspector::ScreencastBackendDispatcherHandler, public CanMakeWeakPtr<InspectorScreencastAgent> {
+    WTF_MAKE_NONCOPYABLE(InspectorScreencastAgent);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    InspectorScreencastAgent(PageAgentContext&);
+    ~InspectorScreencastAgent() override;
+
+    void didCreateFrontendAndBackend(Inspector::FrontendRouter*, Inspector::BackendDispatcher*) override;
+    void willDestroyFrontendAndBackend(Inspector::DisconnectReason) override;
+
+    void start(Inspector::ErrorString&, const String& format, const int* quality) override;
+    void stop(Inspector::ErrorString&) override;
+    void frameAck(Inspector::ErrorString&) override;
+    void startVideoRecording(Inspector::ErrorString&, const String& file, int width, int height, const double* scale) override;
+    void stopVideoRecording(Ref<StopVideoRecordingCallback>&&) override;
+
+    void willDisplay();
+
+private:
+    bool isEnabled() const;
+    String takeSnapshot();
+
+    std::unique_ptr<Inspector::ScreencastFrontendDispatcher> m_frontendDispatcher;
+    Ref<Inspector::ScreencastBackendDispatcher> m_backendDispatcher;
+    Page& m_inspectedPage;
+    int m_inflightFrames { 0 };
+    String m_format;
+    Optional<int> m_quality;
+};
+
+} // namespace WebCore
+
+#endif // PLATFORM(WPE) || PLATFORM(WIN)
diff --git a/Source/WebCore/inspector/agents/InspectorWorkerAgent.cpp b/Source/WebCore/inspector/agents/InspectorWorkerAgent.cpp
index 909c466f87e9bfa8c4c1728c46ad6e7e5907b46e..b4c53ba9dee0e7bb070fe03150339b2abe5efc2c 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().string(), proxy.name());
+    ASSERT(is<Document>(proxy.scriptExecutionContext()));
+    Document& document = downcast<Document>(*proxy.scriptExecutionContext());
+    auto* pageAgent = m_instrumentingAgents.enabledPageAgent();
+    m_frontendDispatcher->workerCreated(proxy.identifier(), proxy.url().string(), proxy.name(),
+        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 50cc98b3fa30e3da1f6e5edd291c9cc663166e71..74d6f7a9a8374ffa92a38ca9244d3fcdc13a585e 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 e8ab5f4c89ade4fc85c042b43433b726563abdd2..ce3b87ef1bdcd29c4fff2cfa735b9d1bc76e1f36 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 c7a25c86b9f61c8ea00c135973225177bdc4ecbe..3b743ddc18fcf10f860df6489c5aacec4d5af752 100644
--- a/Source/WebCore/loader/DocumentLoader.cpp
+++ b/Source/WebCore/loader/DocumentLoader.cpp
@@ -1304,8 +1304,6 @@ 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 c694e0e9369179d2e7c67637999b9788163ed99f..9f969f0d93e5f8e9a0c94b399a5357734e6b1b6b 100644
--- a/Source/WebCore/loader/DocumentLoader.h
+++ b/Source/WebCore/loader/DocumentLoader.h
@@ -170,9 +170,13 @@ 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 124681f5c7ed386ff50466c228950473387226dd..01011adc50c5e80570e5d80f2d28713f85bd519a 100644
--- a/Source/WebCore/loader/FrameLoader.cpp
+++ b/Source/WebCore/loader/FrameLoader.cpp
@@ -1184,6 +1184,7 @@ 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();
@@ -1495,6 +1496,7 @@ void FrameLoader::load(FrameLoadRequest&& request)
 
 void FrameLoader::loadWithNavigationAction(const ResourceRequest& request, NavigationAction&& action, FrameLoadType type, RefPtr<FormState>&& formState, AllowNavigationToInvalidURL allowNavigationToInvalidURL, 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()));
@@ -1598,6 +1600,8 @@ 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 };
 
@@ -3150,6 +3154,8 @@ 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)
@@ -3909,9 +3915,6 @@ 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)
@@ -3920,13 +3923,13 @@ void FrameLoader::dispatchDidClearWindowObjectsInAllWorlds()
 
 void FrameLoader::dispatchDidClearWindowObjectInWorld(DOMWrapperWorld& world)
 {
-    if (!m_frame.script().canExecuteScripts(NotAboutToExecuteScript) || !m_frame.windowProxy().existingJSWindowProxy(world))
-        return;
-
-    m_client->dispatchDidClearWindowObjectInWorld(world);
+    if (m_frame.windowProxy().existingJSWindowProxy(world)) {
+        if (m_frame.script().canExecuteScripts(NotAboutToExecuteScript))
+            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 579d9038f317d45d27c84a27e3f21cff0ae8fddf..9dc41a6ff78b85e229927409b309e01adce2f27a 100644
--- a/Source/WebCore/loader/LoaderStrategy.h
+++ b/Source/WebCore/loader/LoaderStrategy.h
@@ -80,6 +80,7 @@ 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/PolicyChecker.cpp b/Source/WebCore/loader/PolicyChecker.cpp
index 276148a63f36cc46ae0cf2bb535c33f2aa07e30b..998e983870098b620cf154819379aa0b039f7e66 100644
--- a/Source/WebCore/loader/PolicyChecker.cpp
+++ b/Source/WebCore/loader/PolicyChecker.cpp
@@ -46,6 +46,7 @@
 #include "HTMLFormElement.h"
 #include "HTMLFrameOwnerElement.h"
 #include "HTMLPlugInElement.h"
+#include "InspectorInstrumentation.h"
 #include "Logging.h"
 #include <wtf/CompletionHandler.h>
 
@@ -259,26 +260,32 @@ void FrameLoader::PolicyChecker::checkNewWindowPolicy(NavigationAction&& navigat
 
     auto blobURLLifetimeExtension = extendBlobURLLifetimeIfNecessary(request, nullptr);
 
+    InspectorInstrumentation::willCheckNewWindowPolicy(m_frame, request.url());
     auto requestIdentifier = PolicyCheckIdentifier::create();
     m_frame.loader().client().dispatchDecidePolicyForNewWindowAction(navigationAction, request, formState.get(), frameName, requestIdentifier, [frame = makeRef(m_frame), request,
         formState = WTFMove(formState), frameName, navigationAction, function = WTFMove(function), blobURLLifetimeExtension = WTFMove(blobURLLifetimeExtension),
         requestIdentifier] (PolicyAction policyAction, PolicyCheckIdentifier responseIdentifier) mutable {
 
-        if (!responseIdentifier.isValidFor(requestIdentifier))
+        if (!responseIdentifier.isValidFor(requestIdentifier)) {
+            InspectorInstrumentation::didCheckNewWindowPolicy(frame.get(), false);
             return function({ }, nullptr, { }, { }, ShouldContinuePolicyCheck::No);
+        }
 
         switch (policyAction) {
         case PolicyAction::Download:
             frame->loader().client().startDownload(request);
             FALLTHROUGH;
         case PolicyAction::Ignore:
+            InspectorInstrumentation::didCheckNewWindowPolicy(frame.get(), false);
             function({ }, nullptr, { }, { }, ShouldContinuePolicyCheck::No);
             return;
         case PolicyAction::StopAllLoads:
             ASSERT_NOT_REACHED();
+            InspectorInstrumentation::didCheckNewWindowPolicy(frame.get(), false);
             function({ }, nullptr, { }, { }, ShouldContinuePolicyCheck::No);
             return;
         case PolicyAction::Use:
+            InspectorInstrumentation::didCheckNewWindowPolicy(frame.get(), true);
             function(request, makeWeakPtr(formState.get()), frameName, navigationAction, ShouldContinuePolicyCheck::Yes);
             return;
         }
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/ChromeClient.h b/Source/WebCore/page/ChromeClient.h
index 71e3805992899205536e0bf599ace82f2e56a36a..e33516252fefd5f87144c6cef6916f9c372dd065 100644
--- a/Source/WebCore/page/ChromeClient.h
+++ b/Source/WebCore/page/ChromeClient.h
@@ -277,7 +277,7 @@ public:
 #endif
 
 #if ENABLE(ORIENTATION_EVENTS)
-    virtual int deviceOrientation() const = 0;
+    virtual int deviceOrientation() const { return 0; }
 #endif
 
 #if ENABLE(INPUT_TYPE_COLOR)
diff --git a/Source/WebCore/page/EventHandler.cpp b/Source/WebCore/page/EventHandler.cpp
index 5e3db4ddbb8a0b4bd9a2264ae5455f5234edaba9..90df915d0506def14f4eac3abedad3a0757a59c1 100644
--- a/Source/WebCore/page/EventHandler.cpp
+++ b/Source/WebCore/page/EventHandler.cpp
@@ -837,9 +837,7 @@ 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;
@@ -878,8 +876,6 @@ VisiblePosition EventHandler::selectionExtentRespectingEditingBoundary(const Vis
     return targetNode->renderer()->positionForPoint(LayoutPoint(selectionEndPoint), nullptr);
 }
 
-#if ENABLE(DRAG_SUPPORT)
-
 #if !PLATFORM(IOS_FAMILY)
 
 bool EventHandler::supportsSelectionUpdatesOnMouseDrag() const
@@ -901,8 +897,10 @@ 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)
@@ -923,7 +921,9 @@ 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);
@@ -940,6 +940,8 @@ 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
@@ -971,6 +973,8 @@ 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())
@@ -1062,7 +1066,6 @@ void EventHandler::updateSelectionForMouseDrag(const HitTestResult& hitTestResul
     m_frame.selection().setSelectionByMouseIfDifferent(newSelection, m_frame.selection().granularity(),
         FrameSelection::EndPointsAdjustmentMode::AdjustAtBidiBoundary);
 }
-#endif // ENABLE(DRAG_SUPPORT)
 
 void EventHandler::lostMouseCapture()
 {
@@ -1110,9 +1113,7 @@ 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;
@@ -2073,10 +2074,8 @@ bool EventHandler::handleMouseMoveEvent(const PlatformMouseEvent& platformMouseE
     
     swallowEvent = !dispatchMouseEvent(eventNames().mousemoveEvent, mouseEvent.targetNode(), 0, platformMouseEvent, FireMouseOverOut::Yes);
 
-#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 f7a16c1e06299f7a663928ef1193229a5874e032..854dec2823111417c1ce42a2948d0030886e5ac6 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();
@@ -364,10 +362,8 @@ 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&);
 
@@ -464,10 +460,8 @@ private:
     void defaultTabEventHandler(KeyboardEvent&);
     void defaultArrowEventHandler(FocusDirection, KeyboardEvent&);
 
-#if ENABLE(DRAG_SUPPORT)
     OptionSet<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.
@@ -475,9 +469,10 @@ 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);
     
@@ -528,10 +523,7 @@ private:
     enum SelectionInitiationState { HaveNotStartedSelection, PlacedCaret, ExtendedSelection };
     SelectionInitiationState m_selectionInitiationState { HaveNotStartedSelection };
 
-#if ENABLE(DRAG_SUPPORT)
     LayoutPoint m_dragStartPosition;
-#endif
-
     Timer m_hoverTimer;
     bool m_hasScheduledCursorUpdate { false };
 
diff --git a/Source/WebCore/page/EventSource.cpp b/Source/WebCore/page/EventSource.cpp
index 757765c3b4872d5a6f92b34e3f2ac67eaaf2dd82..69c4ef67941cee93213ccac1aa04d2cb1db08782 100644
--- a/Source/WebCore/page/EventSource.cpp
+++ b/Source/WebCore/page/EventSource.cpp
@@ -36,6 +36,7 @@
 #include "CachedResourceRequestInitiators.h"
 #include "ContentSecurityPolicy.h"
 #include "EventNames.h"
+#include "InspectorNetworkAgent.h"
 #include "MessageEvent.h"
 #include "ResourceError.h"
 #include "ResourceRequest.h"
@@ -97,6 +98,7 @@ void EventSource::connect()
     ASSERT(!m_requestInFlight);
 
     ResourceRequest request { m_url };
+    request.setInitiatorIdentifier(InspectorNetworkAgent::initiatorIdentifierForEventSource());
     request.setHTTPMethod("GET");
     request.setHTTPHeaderField(HTTPHeaderName::Accept, "text/event-stream");
     request.setHTTPHeaderField(HTTPHeaderName::CacheControl, "no-cache");
diff --git a/Source/WebCore/page/Frame.cpp b/Source/WebCore/page/Frame.cpp
index d04fa0c39e0eb9a83ccd864e42ae3042b9928308..b9c1761f676c13822ab20ae0abc979c9629f4cb8 100644
--- a/Source/WebCore/page/Frame.cpp
+++ b/Source/WebCore/page/Frame.cpp
@@ -182,6 +182,7 @@ Frame::Frame(Page& page, HTMLFrameOwnerElement* ownerElement, UniqueRef<FrameLoa
 void Frame::init()
 {
     m_loader->init();
+    InspectorInstrumentation::frameAttached(this);
 }
 
 Ref<Frame> Frame::create(Page* page, HTMLFrameOwnerElement* ownerElement, UniqueRef<FrameLoaderClient>&& client)
@@ -341,7 +342,7 @@ void Frame::orientationChanged()
 int Frame::orientation() const
 {
     if (m_page)
-        return m_page->chrome().client().deviceOrientation();
+        return m_page->orientation();
     return 0;
 }
 #endif // ENABLE(ORIENTATION_EVENTS)
diff --git a/Source/WebCore/page/FrameSnapshotting.cpp b/Source/WebCore/page/FrameSnapshotting.cpp
index 73587787f88a6ad4e4baffb0beb0b87e7782916f..88492f501e6ec9e38455dbe6fd27537bf0ee6970 100644
--- a/Source/WebCore/page/FrameSnapshotting.cpp
+++ b/Source/WebCore/page/FrameSnapshotting.cpp
@@ -114,7 +114,12 @@ std::unique_ptr<ImageBuffer> snapshotFrameRectWithClip(Frame& frame, const IntRe
     std::unique_ptr<ImageBuffer> buffer = ImageBuffer::create(imageRect.size(), RenderingMode::Unaccelerated, scaleFactor);
     if (!buffer)
         return nullptr;
+#if !PLATFORM(MAC)
+    buffer->context().scale(scaleFactor);
+#endif
     buffer->context().translate(-imageRect.x(), -imageRect.y());
+    if (coordinateSpace != FrameView::ViewCoordinates)
+      buffer->context().scale(1 / frame.page()->pageScaleFactor());
 
     if (!clipRects.isEmpty()) {
         Path clipPath;
@@ -123,7 +128,10 @@ std::unique_ptr<ImageBuffer> snapshotFrameRectWithClip(Frame& frame, const IntRe
         buffer->context().clipPath(clipPath);
     }
 
-    frame.view()->paintContentsForSnapshot(buffer->context(), imageRect, shouldIncludeSelection, coordinateSpace);
+    FloatRect fr = imageRect;
+    if (coordinateSpace != FrameView::ViewCoordinates)
+      fr.scale(frame.page()->pageScaleFactor());
+    frame.view()->paintContentsForSnapshot(buffer->context(), enclosingIntRect(fr), shouldIncludeSelection, coordinateSpace);
     return buffer;
 }
 
diff --git a/Source/WebCore/page/FrameView.cpp b/Source/WebCore/page/FrameView.cpp
index 971f555799fdfc4b17b43130ec00175f16389c28..178f2a09f57e5fb2e2f1f650fb93e923f6f1709b 100644
--- a/Source/WebCore/page/FrameView.cpp
+++ b/Source/WebCore/page/FrameView.cpp
@@ -2987,7 +2987,7 @@ 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 38fd7b29b53eab484e30963b51c8ae525c5d7a38..37b2a2b8baeba64a50f12c773f2a1072595806c5 100644
--- a/Source/WebCore/page/History.cpp
+++ b/Source/WebCore/page/History.cpp
@@ -260,6 +260,7 @@ 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 ddab06d8c1358e160d7b25cf3d96cab90dc291a6..9863fbb9ad07bb7b2be32bd5dcc6faa3176ca398 100644
--- a/Source/WebCore/page/Page.cpp
+++ b/Source/WebCore/page/Page.cpp
@@ -90,6 +90,7 @@
 #include "PerformanceLoggingClient.h"
 #include "PerformanceMonitor.h"
 #include "PlatformMediaSessionManager.h"
+#include "PlatformScreen.h"
 #include "PlatformStrategies.h"
 #include "PlugInClient.h"
 #include "PluginData.h"
@@ -429,6 +430,37 @@ 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();
+}
+
+#if ENABLE(ORIENTATION_EVENTS)
+int Page::orientation() const
+{
+    return m_overrideOrientation.valueOr(chrome().client().deviceOrientation());
+}
+
+void Page::setOverrideOrientation(Optional<int> orientation)
+{
+    if (orientation == m_overrideOrientation)
+        return;
+
+    m_overrideOrientation = orientation;
+    mainFrame().orientationChanged();
+}
+#endif
+
 ScrollingCoordinator* Page::scrollingCoordinator()
 {
     if (!m_scrollingCoordinator && m_settings->scrollingCoordinatorEnabled()) {
diff --git a/Source/WebCore/page/Page.h b/Source/WebCore/page/Page.h
index 101a265f470cdb63b2611e64d0e131e392c236de..f75c84a349dbad560d965ea5f81cb0399b7f54e3 100644
--- a/Source/WebCore/page/Page.h
+++ b/Source/WebCore/page/Page.h
@@ -195,6 +195,9 @@ public:
     const Optional<ViewportArguments>& overrideViewportArguments() const { return m_overrideViewportArguments; }
     WEBCORE_EXPORT void setOverrideViewportArguments(const Optional<ViewportArguments>&);
 
+    WEBCORE_EXPORT FloatSize screenSize();
+    void setOverrideScreenSize(Optional<FloatSize> size);
+
     static void refreshPlugins(bool reload);
     WEBCORE_EXPORT PluginData& pluginData();
     void clearPluginData();
@@ -743,6 +746,11 @@ public:
 
     WEBCORE_EXPORT Vector<Ref<Element>> editableElementsInRect(const FloatRect&) const;
 
+#if ENABLE(ORIENTATION_EVENTS)
+    int orientation() const;
+    void setOverrideOrientation(Optional<int>);
+#endif
+
 #if ENABLE(DEVICE_ORIENTATION) && PLATFORM(IOS_FAMILY)
     DeviceOrientationUpdateProvider* deviceOrientationUpdateProvider() const { return m_deviceOrientationUpdateProvider.get(); }
 #endif
@@ -1039,6 +1047,11 @@ private:
 #endif
 
     Optional<ViewportArguments> m_overrideViewportArguments;
+    Optional<FloatSize> m_overrideScreenSize;
+
+#if ENABLE(ORIENTATION_EVENTS)
+    Optional<int> m_overrideOrientation;
+#endif
 
 #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/SocketProvider.cpp b/Source/WebCore/page/SocketProvider.cpp
index 803ac83155ff4df1becf75cd4710f6fbf7bbc32a..cc08682748a6d2fdf5d79980cd629812c98aa7ce 100644
--- a/Source/WebCore/page/SocketProvider.cpp
+++ b/Source/WebCore/page/SocketProvider.cpp
@@ -33,7 +33,7 @@ namespace WebCore {
     
 Ref<SocketStreamHandle> SocketProvider::createSocketStreamHandle(const URL& url, SocketStreamHandleClient& client, PAL::SessionID sessionID, const String& credentialPartition, const StorageSessionProvider* provider)
 {
-    return SocketStreamHandleImpl::create(url, client, sessionID, credentialPartition, { }, provider);
+    return SocketStreamHandleImpl::create(url, false, client, sessionID, credentialPartition, { }, provider);
 }
 
 RefPtr<ThreadableWebSocketChannel> SocketProvider::createWebSocketChannel(Document&, WebSocketChannelClient&)
diff --git a/Source/WebCore/page/csp/ContentSecurityPolicy.cpp b/Source/WebCore/page/csp/ContentSecurityPolicy.cpp
index 664be618eeb9989a3e6cd6b0c16eea8782a6b27f..6a406b116549b8b54a4a834521555470bf5f71a2 100644
--- a/Source/WebCore/page/csp/ContentSecurityPolicy.cpp
+++ b/Source/WebCore/page/csp/ContentSecurityPolicy.cpp
@@ -297,6 +297,8 @@ 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)
@@ -310,6 +312,8 @@ 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) {
@@ -326,6 +330,8 @@ 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/Cairo.cmake b/Source/WebCore/platform/Cairo.cmake
index fc6c5f3cd046269566822c08a482cc3bd6a883c0..083c03903a3111ee2cb6f9882dd2efe146d7dc35 100644
--- a/Source/WebCore/platform/Cairo.cmake
+++ b/Source/WebCore/platform/Cairo.cmake
@@ -17,6 +17,7 @@ list(APPEND WebCore_PRIVATE_FRAMEWORK_HEADERS
     platform/graphics/cairo/ImageBufferCairoGLSurfaceBackend.h
     platform/graphics/cairo/ImageBufferCairoImageSurfaceBackend.h
     platform/graphics/cairo/ImageBufferCairoSurfaceBackend.h
+    platform/graphics/cairo/ImageBufferUtilitiesCairo.h
     platform/graphics/cairo/PlatformContextCairo.h
     platform/graphics/cairo/RefPtrCairo.h
 )
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 892d8de6d345d91fda80cfa5334c4aa68b757da3..a22497d801a349487be10b15139e9c761a4a3ea5 100644
--- a/Source/WebCore/platform/ScrollableArea.h
+++ b/Source/WebCore/platform/ScrollableArea.h
@@ -110,7 +110,7 @@ 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/cairo/ImageBufferUtilitiesCairo.cpp b/Source/WebCore/platform/graphics/cairo/ImageBufferUtilitiesCairo.cpp
index d79728555b7db9b59cb615c55a7a7a6851cb57c8..61d3cc4b488e35ef9e1afa1ce3ac5f5d60ebe9a7 100644
--- a/Source/WebCore/platform/graphics/cairo/ImageBufferUtilitiesCairo.cpp
+++ b/Source/WebCore/platform/graphics/cairo/ImageBufferUtilitiesCairo.cpp
@@ -48,6 +48,13 @@
 #include <wtf/glib/GUniquePtr.h>
 #endif
 
+#if PLATFORM(WPE) || PLATFORM(WIN)
+#include <stdio.h> // Needed by jpeglib.h for FILE.
+extern "C" {
+#include "jpeglib.h"
+}
+#endif
+
 namespace WebCore {
 
 #if !PLATFORM(GTK)
@@ -65,8 +72,75 @@ static bool encodeImage(cairo_surface_t* image, const String& mimeType, Vector<u
     return cairo_surface_write_to_png_stream(image, writeFunction, output) == CAIRO_STATUS_SUCCESS;
 }
 
-Vector<uint8_t> data(cairo_surface_t* image, const String& mimeType, Optional<double>)
+static Vector<uint8_t> encodeJpeg(cairo_surface_t* image, int quality)
+{
+    if (cairo_surface_get_type(image) != CAIRO_SURFACE_TYPE_IMAGE) {
+        fprintf(stderr, "Unexpected cairo surface type: %d\n", cairo_surface_get_type(image));
+        return { };
+    }
+
+    if (cairo_image_surface_get_format(image) != CAIRO_FORMAT_ARGB32) {
+        fprintf(stderr, "Unexpected surface image format: %d\n", cairo_image_surface_get_format(image));
+        return { };
+    }
+
+    struct jpeg_compress_struct info;
+    struct jpeg_error_mgr error;
+    info.err = jpeg_std_error(&error);
+    jpeg_create_compress(&info);
+
+    unsigned char* bufferPtr = nullptr;
+    unsigned long bufferSize;
+    jpeg_mem_dest(&info, &bufferPtr, &bufferSize);
+    info.image_width = cairo_image_surface_get_width(image);
+    info.image_height = cairo_image_surface_get_height(image);
+
+#ifndef LIBJPEG_TURBO_VERSION
+    COMPILE_ASSERT(false, only_libjpeg_turbo_is_supported);
+#endif
+
+#if CPU(LITTLE_ENDIAN)
+    info.in_color_space = JCS_EXT_BGRA;
+#else
+    info.in_color_space = JCS_EXT_ARGB;
+#endif
+    // # of color components in input image
+    info.input_components = 4;
+
+    jpeg_set_defaults(&info);
+    jpeg_set_quality(&info, quality, true);
+
+    jpeg_start_compress(&info, true);
+
+    while (info.next_scanline < info.image_height)
+    {
+        JSAMPROW row = cairo_image_surface_get_data(image) + (info.next_scanline * cairo_image_surface_get_stride(image));
+        if (jpeg_write_scanlines(&info, &row, 1) != 1) {
+            fprintf(stderr, "JPEG library failed to encode line\n");
+            break;
+        }
+    }
+
+    jpeg_finish_compress(&info);
+    jpeg_destroy_compress(&info);
+
+    Vector<uint8_t> output;
+    output.append(bufferPtr, bufferSize);
+    // Cannot use unique_ptr as bufferPtr changes during compression. GUniquePtr would work
+    // but it's under GLib and won't work on Windows.
+    free(bufferPtr);
+    return output;
+}
+
+Vector<uint8_t> data(cairo_surface_t* image, const String& mimeType, Optional<double> quality)
 {
+    if (mimeType == "image/jpeg") {
+        int qualityPercent = 100;
+        if (quality)
+            qualityPercent = static_cast<int>(*quality * 100.0 + 0.5);
+        return encodeJpeg(image, qualityPercent);
+    }
+
     Vector<uint8_t> encodedImage;
     if (!image || !encodeImage(image, mimeType, &encodedImage))
         return { };
diff --git a/Source/WebCore/platform/graphics/cg/ImageBufferUtilitiesCG.h b/Source/WebCore/platform/graphics/cg/ImageBufferUtilitiesCG.h
index bc87758878d5163a938af8242c7a6800ea9bd13c..3d0751f8dfe1124bbe054daa2fa0c7552fecab32 100644
--- a/Source/WebCore/platform/graphics/cg/ImageBufferUtilitiesCG.h
+++ b/Source/WebCore/platform/graphics/cg/ImageBufferUtilitiesCG.h
@@ -42,7 +42,7 @@ WEBCORE_EXPORT uint8_t verifyImageBufferIsBigEnough(const void* buffer, size_t b
 CFStringRef jpegUTI();
 RetainPtr<CFStringRef> utiFromImageBufferMIMEType(const String&);
 
-bool encodeImage(CGImageRef, CFStringRef uti, Optional<double> quality, CFMutableDataRef);
+WEBCORE_EXPORT bool encodeImage(CGImageRef, CFStringRef uti, Optional<double> quality, CFMutableDataRef);
 
 String dataURL(CFDataRef, const String& mimeType);
 String dataURL(const ImageData&, const String& mimeType, Optional<double> quality);
diff --git a/Source/WebCore/platform/graphics/opengl/GraphicsContextGLOpenGLBase.cpp b/Source/WebCore/platform/graphics/opengl/GraphicsContextGLOpenGLBase.cpp
index 445c7d78a4a1a8cdb0e08a859d3912e5cc62b6c6..93a8006dd5237018b573b976d0bbe28f02b8254f 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 0516e70973e0078de6ad0216375d34dd9ef51a8d..ffd9a02deb5518e0c8c77b156815c11eb4b16829 100644
--- a/Source/WebCore/platform/gtk/PlatformKeyboardEventGtk.cpp
+++ b/Source/WebCore/platform/gtk/PlatformKeyboardEventGtk.cpp
@@ -37,8 +37,10 @@
 #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 {
 
@@ -1294,6 +1296,246 @@ 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/network/cf/SocketStreamHandleImpl.h b/Source/WebCore/platform/network/cf/SocketStreamHandleImpl.h
index d677280d2b5e7b053a240c155d64bc881f1737bb..1be949e09982b34366d162e6d45ebc51a76dcfb0 100644
--- a/Source/WebCore/platform/network/cf/SocketStreamHandleImpl.h
+++ b/Source/WebCore/platform/network/cf/SocketStreamHandleImpl.h
@@ -47,7 +47,7 @@ class SocketStreamHandleClient;
 
 class SocketStreamHandleImpl : public SocketStreamHandle {
 public:
-    static Ref<SocketStreamHandleImpl> create(const URL& url, SocketStreamHandleClient& client, PAL::SessionID sessionID, const String& credentialPartition, SourceApplicationAuditToken&& auditData, const StorageSessionProvider* provider) { return adoptRef(*new SocketStreamHandleImpl(url, client, sessionID, credentialPartition, WTFMove(auditData), provider)); }
+    static Ref<SocketStreamHandleImpl> create(const URL& url, bool ignoreCertificateErrors, SocketStreamHandleClient& client, PAL::SessionID sessionID, const String& credentialPartition, SourceApplicationAuditToken&& auditData, const StorageSessionProvider* provider) { return adoptRef(*new SocketStreamHandleImpl(url, ignoreCertificateErrors, client, sessionID, credentialPartition, WTFMove(auditData), provider)); }
 
     virtual ~SocketStreamHandleImpl();
 
@@ -61,7 +61,7 @@ private:
     Optional<size_t> platformSendInternal(const uint8_t*, size_t);
     bool sendPendingData();
 
-    WEBCORE_EXPORT SocketStreamHandleImpl(const URL&, SocketStreamHandleClient&, PAL::SessionID, const String& credentialPartition, SourceApplicationAuditToken&&, const StorageSessionProvider*);
+    WEBCORE_EXPORT SocketStreamHandleImpl(const URL&, bool ignoreCertificateErrors, SocketStreamHandleClient&, PAL::SessionID, const String& credentialPartition, SourceApplicationAuditToken&&, const StorageSessionProvider*);
     void createStreams();
     void scheduleStreams();
     void chooseProxy();
@@ -106,6 +106,7 @@ private:
     String m_credentialPartition;
     SourceApplicationAuditToken m_auditData;
     RefPtr<const StorageSessionProvider> m_storageSessionProvider;
+    bool m_ignoreCertificateErrors { false };
 
     StreamBuffer<uint8_t, 1024 * 1024> m_buffer;
     static const unsigned maxBufferSize = 100 * 1024 * 1024;
diff --git a/Source/WebCore/platform/network/cf/SocketStreamHandleImplCFNet.cpp b/Source/WebCore/platform/network/cf/SocketStreamHandleImplCFNet.cpp
index 545c28e62f72771de5f3f3e9fed2e8cf6147ed0f..a6fc5f5b3fc62adce2604821bd29f9aed378c24c 100644
--- a/Source/WebCore/platform/network/cf/SocketStreamHandleImplCFNet.cpp
+++ b/Source/WebCore/platform/network/cf/SocketStreamHandleImplCFNet.cpp
@@ -96,7 +96,7 @@ static inline auto callbacksRunLoopMode()
 #endif
 }
 
-SocketStreamHandleImpl::SocketStreamHandleImpl(const URL& url, SocketStreamHandleClient& client, PAL::SessionID sessionID, const String& credentialPartition, SourceApplicationAuditToken&& auditData, const StorageSessionProvider* provider)
+SocketStreamHandleImpl::SocketStreamHandleImpl(const URL& url, bool ignoreCertificateErrors, SocketStreamHandleClient& client, PAL::SessionID sessionID, const String& credentialPartition, SourceApplicationAuditToken&& auditData, const StorageSessionProvider* provider)
     : SocketStreamHandle(url, client)
     , m_connectingSubstate(New)
     , m_connectionType(Unknown)
@@ -104,6 +104,7 @@ SocketStreamHandleImpl::SocketStreamHandleImpl(const URL& url, SocketStreamHandl
     , m_credentialPartition(credentialPartition)
     , m_auditData(WTFMove(auditData))
     , m_storageSessionProvider(provider)
+    , m_ignoreCertificateErrors(ignoreCertificateErrors)
 {
     LOG(Network, "SocketStreamHandle %p new client %p", this, &m_client);
 
@@ -360,7 +361,7 @@ void SocketStreamHandleImpl::createStreams()
     }
 
     if (shouldUseSSL()) {
-        CFBooleanRef validateCertificateChain = DeprecatedGlobalSettings::allowsAnySSLCertificate() ? kCFBooleanFalse : kCFBooleanTrue;
+        CFBooleanRef validateCertificateChain = m_ignoreCertificateErrors || DeprecatedGlobalSettings::allowsAnySSLCertificate() ? kCFBooleanFalse : kCFBooleanTrue;
         const void* keys[] = {
             kCFStreamSSLPeerName,
             kCFStreamSSLLevel,
diff --git a/Source/WebCore/platform/network/curl/CookieJarDB.h b/Source/WebCore/platform/network/curl/CookieJarDB.h
index 7c0ea47ece4ff0d472ce595c91ea1cfa90b25ca7..1c44229a18fe90f6e5e0c0056dddd09acadfe49b 100644
--- a/Source/WebCore/platform/network/curl/CookieJarDB.h
+++ b/Source/WebCore/platform/network/curl/CookieJarDB.h
@@ -72,7 +72,7 @@ public:
     WEBCORE_EXPORT ~CookieJarDB();
 
 private:
-    CookieAcceptPolicy m_acceptPolicy { CookieAcceptPolicy::Always };
+    CookieAcceptPolicy m_acceptPolicy { CookieAcceptPolicy::OnlyFromMainDocumentDomain };
     String m_databasePath;
 
     bool m_detectedDatabaseCorruption { false };
diff --git a/Source/WebCore/platform/network/curl/CurlStream.cpp b/Source/WebCore/platform/network/curl/CurlStream.cpp
index 26dc7bef4b74bc6b4e2e526dec6523c3ad6d3643..c783aa5a7984f3966312e5e0ffd76f93ed6208f8 100644
--- a/Source/WebCore/platform/network/curl/CurlStream.cpp
+++ b/Source/WebCore/platform/network/curl/CurlStream.cpp
@@ -33,7 +33,7 @@
 
 namespace WebCore {
 
-CurlStream::CurlStream(CurlStreamScheduler& scheduler, CurlStreamID streamID, URL&& url)
+CurlStream::CurlStream(CurlStreamScheduler& scheduler, CurlStreamID streamID, bool ignoreCertificateErrors, URL&& url)
     : m_scheduler(scheduler)
     , m_streamID(streamID)
 {
@@ -49,6 +49,9 @@ CurlStream::CurlStream(CurlStreamScheduler& scheduler, CurlStreamID streamID, UR
     m_curlHandle->setUrl(urlForConnection);
 
     m_curlHandle->enableConnectionOnly();
+    if (ignoreCertificateErrors)
+        m_curlHandle->disableServerTrustEvaluation();
+
 
     auto errorCode = m_curlHandle->perform();
     if (errorCode != CURLE_OK) {
diff --git a/Source/WebCore/platform/network/curl/CurlStream.h b/Source/WebCore/platform/network/curl/CurlStream.h
index 313b0173da5cd404a1e3fcad9573b8ff7c3abd4f..020980a0f61d47e8c7929bfaab2f8394d014766d 100644
--- a/Source/WebCore/platform/network/curl/CurlStream.h
+++ b/Source/WebCore/platform/network/curl/CurlStream.h
@@ -50,12 +50,12 @@ public:
         virtual void didFail(CurlStreamID, CURLcode) = 0;
     };
 
-    static std::unique_ptr<CurlStream> create(CurlStreamScheduler& scheduler, CurlStreamID streamID, URL&& url)
+    static std::unique_ptr<CurlStream> create(CurlStreamScheduler& scheduler, CurlStreamID streamID, bool ignoreCertificateErrors, URL&& url)
     {
-        return WTF::makeUnique<CurlStream>(scheduler, streamID, WTFMove(url));
+        return WTF::makeUnique<CurlStream>(scheduler, streamID, ignoreCertificateErrors, WTFMove(url));
     }
 
-    CurlStream(CurlStreamScheduler&, CurlStreamID, URL&&);
+    CurlStream(CurlStreamScheduler&, CurlStreamID, bool ignoreCertificateErrors, URL&&);
     virtual ~CurlStream();
 
     void send(UniqueArray<uint8_t>&&, size_t);
diff --git a/Source/WebCore/platform/network/curl/CurlStreamScheduler.cpp b/Source/WebCore/platform/network/curl/CurlStreamScheduler.cpp
index 3fb8759984aa31a7d44baa2f69afe2fee461ea4f..bb7ad47477d97fa1eaff5d3da6b9a3705ff1e32f 100644
--- a/Source/WebCore/platform/network/curl/CurlStreamScheduler.cpp
+++ b/Source/WebCore/platform/network/curl/CurlStreamScheduler.cpp
@@ -40,7 +40,7 @@ CurlStreamScheduler::~CurlStreamScheduler()
     ASSERT(isMainThread());
 }
 
-CurlStreamID CurlStreamScheduler::createStream(const URL& url, CurlStream::Client& client)
+CurlStreamID CurlStreamScheduler::createStream(const URL& url, bool ignoreCertificateErrors, CurlStream::Client& client)
 {
     ASSERT(isMainThread());
 
@@ -51,8 +51,8 @@ CurlStreamID CurlStreamScheduler::createStream(const URL& url, CurlStream::Clien
     auto streamID = m_currentStreamID;
     m_clientList.add(streamID, &client);
 
-    callOnWorkerThread([this, streamID, url = url.isolatedCopy()]() mutable {
-        m_streamList.add(streamID, CurlStream::create(*this, streamID, WTFMove(url)));
+    callOnWorkerThread([this, streamID, ignoreCertificateErrors, url = url.isolatedCopy()]() mutable {
+        m_streamList.add(streamID, CurlStream::create(*this, streamID, ignoreCertificateErrors, WTFMove(url)));
     });
 
     return streamID;
diff --git a/Source/WebCore/platform/network/curl/CurlStreamScheduler.h b/Source/WebCore/platform/network/curl/CurlStreamScheduler.h
index 7d881206c9689f433227969c9b7f9ff268bdaaed..2e8118f11f87fa5f32adcedc165aec8220b36d58 100644
--- a/Source/WebCore/platform/network/curl/CurlStreamScheduler.h
+++ b/Source/WebCore/platform/network/curl/CurlStreamScheduler.h
@@ -38,7 +38,7 @@ public:
     CurlStreamScheduler();
     virtual ~CurlStreamScheduler();
 
-    CurlStreamID createStream(const URL&, CurlStream::Client&);
+    CurlStreamID createStream(const URL&, bool ignoreCertificateErrors, CurlStream::Client&);
     void destroyStream(CurlStreamID);
     void send(CurlStreamID, UniqueArray<uint8_t>&&, size_t);
 
diff --git a/Source/WebCore/platform/network/curl/SocketStreamHandleImpl.h b/Source/WebCore/platform/network/curl/SocketStreamHandleImpl.h
index fad4ef9198118f5e6e5ed7d3c14b99e574593451..a2d59843896f252fccdddbb94c5275eec6300f1b 100644
--- a/Source/WebCore/platform/network/curl/SocketStreamHandleImpl.h
+++ b/Source/WebCore/platform/network/curl/SocketStreamHandleImpl.h
@@ -44,7 +44,7 @@ class StorageSessionProvider;
 
 class SocketStreamHandleImpl : public SocketStreamHandle, public CurlStream::Client {
 public:
-    static Ref<SocketStreamHandleImpl> create(const URL& url, SocketStreamHandleClient& client, PAL::SessionID, const String&, SourceApplicationAuditToken&&, const StorageSessionProvider* provider) { return adoptRef(*new SocketStreamHandleImpl(url, client, provider)); }
+    static Ref<SocketStreamHandleImpl> create(const URL& url, bool ignoreCertificateErrors, SocketStreamHandleClient& client, PAL::SessionID, const String&, SourceApplicationAuditToken&&, const StorageSessionProvider* provider) { return adoptRef(*new SocketStreamHandleImpl(url, ignoreCertificateErrors, client, provider)); }
 
     virtual ~SocketStreamHandleImpl();
 
@@ -53,7 +53,7 @@ public:
     WEBCORE_EXPORT void platformClose() final;
 
 private:
-    WEBCORE_EXPORT SocketStreamHandleImpl(const URL&, SocketStreamHandleClient&, const StorageSessionProvider*);
+    WEBCORE_EXPORT SocketStreamHandleImpl(const URL&, bool ignoreCertificateErrors, SocketStreamHandleClient&, const StorageSessionProvider*);
 
     size_t bufferedAmount() final;
     Optional<size_t> platformSendInternal(const uint8_t*, size_t);
diff --git a/Source/WebCore/platform/network/curl/SocketStreamHandleImplCurl.cpp b/Source/WebCore/platform/network/curl/SocketStreamHandleImplCurl.cpp
index cae8c43d60fcf6a3d69c58a7436516f923d227cb..e6b03f378929abbd4437f8507ea2f6c563edcff7 100644
--- a/Source/WebCore/platform/network/curl/SocketStreamHandleImplCurl.cpp
+++ b/Source/WebCore/platform/network/curl/SocketStreamHandleImplCurl.cpp
@@ -43,7 +43,7 @@
 
 namespace WebCore {
 
-SocketStreamHandleImpl::SocketStreamHandleImpl(const URL& url, SocketStreamHandleClient& client, const StorageSessionProvider* provider)
+SocketStreamHandleImpl::SocketStreamHandleImpl(const URL& url, bool ignoreCertificateErrors, SocketStreamHandleClient& client, const StorageSessionProvider* provider)
     : SocketStreamHandle(url, client)
     , m_storageSessionProvider(provider)
     , m_scheduler(CurlContext::singleton().streamScheduler())
@@ -52,7 +52,7 @@ SocketStreamHandleImpl::SocketStreamHandleImpl(const URL& url, SocketStreamHandl
     if (m_url.protocolIs("wss") && DeprecatedGlobalSettings::allowsAnySSLCertificate())
         CurlContext::singleton().sslHandle().setIgnoreSSLErrors(true);
 
-    m_streamID = m_scheduler.createStream(m_url, *this);
+    m_streamID = m_scheduler.createStream(m_url, ignoreCertificateErrors, *this);
 }
 
 SocketStreamHandleImpl::~SocketStreamHandleImpl()
diff --git a/Source/WebCore/platform/network/soup/SocketStreamHandleImpl.h b/Source/WebCore/platform/network/soup/SocketStreamHandleImpl.h
index 3ecf866005da6da9cec7c7930e6a4f93cb39d6e0..d81dc9ac0c433e00ab4ad73e206856098ab9230e 100644
--- a/Source/WebCore/platform/network/soup/SocketStreamHandleImpl.h
+++ b/Source/WebCore/platform/network/soup/SocketStreamHandleImpl.h
@@ -47,7 +47,7 @@ class StorageSessionProvider;
 
 class SocketStreamHandleImpl final : public SocketStreamHandle {
 public:
-    static Ref<SocketStreamHandleImpl> create(const URL&, SocketStreamHandleClient&, PAL::SessionID, const String&, SourceApplicationAuditToken&&, const StorageSessionProvider*)
+    static Ref<SocketStreamHandleImpl> create(const URL&, bool, SocketStreamHandleClient&, PAL::SessionID, const String&, SourceApplicationAuditToken&&, const StorageSessionProvider*)
     {
         RELEASE_ASSERT_NOT_REACHED();
     }
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/WebCore/platform/xr/openxr/PlatformXROpenXR.cpp b/Source/WebCore/platform/xr/openxr/PlatformXROpenXR.cpp
index d03eaafb306b4dc698004a699256760014061d4b..15bfcb30f6bc6b279b96e55ae46dc44bcfaa4b80 100644
--- a/Source/WebCore/platform/xr/openxr/PlatformXROpenXR.cpp
+++ b/Source/WebCore/platform/xr/openxr/PlatformXROpenXR.cpp
@@ -75,10 +75,10 @@ public:
 #endif
 
 private:
-#if USE_OPENXR
     void enumerateApiLayerProperties() const;
     void enumerateInstanceExtensionProperties() const;
 
+#if USE_OPENXR
     XrInstance m_instance { XR_NULL_HANDLE };
 #endif // USE_OPENXR
 };
@@ -139,10 +139,10 @@ Instance::Impl::Impl()
     enumerateApiLayerProperties();
     enumerateInstanceExtensionProperties();
 
+#if USE_OPENXR
     static const char* s_applicationName = "WebXR (WebKit)";
     static const uint32_t s_applicationVersion = 1;
 
-#if USE_OPENXR
     auto createInfo = createStructure<XrInstanceCreateInfo, XR_TYPE_INSTANCE_CREATE_INFO>();
     createInfo.createFlags = 0;
     std::memcpy(createInfo.applicationInfo.applicationName, s_applicationName, XR_MAX_APPLICATION_NAME_SIZE);
@@ -162,7 +162,9 @@ Instance::Impl::Impl()
 
 Instance::Impl::~Impl()
 {
+#if USE_OPENXR
     xrDestroyInstance(m_instance);
+#endif
 }
 
 #if USE_OPENXR
diff --git a/Source/WebKit/NetworkProcess/NetworkProcess.cpp b/Source/WebKit/NetworkProcess/NetworkProcess.cpp
index e6135c62c1ccc00dd2cf05d2a7d41591b30e763b..1709e6ac3bf0e90f9ced1a326958319611dcce5f 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"
@@ -600,6 +599,41 @@ void NetworkProcess::destroySession(PAL::SessionID sessionID)
         webIDBServer->close();
 }
 
+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);
+}
+
+void NetworkProcess::setIgnoreCertificateErrors(PAL::SessionID sessionID, bool ignore)
+{
+    if (auto* networkSession = this->networkSession(sessionID))
+        networkSession->setIgnoreCertificateErrors(ignore);
+}
+
 #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 46d9f51dd6a91e6c692729da6163f0abb2d455f2..aa777a5ae392a8249b9eca952079f375c7935287 100644
--- a/Source/WebKit/NetworkProcess/NetworkProcess.h
+++ b/Source/WebKit/NetworkProcess/NetworkProcess.h
@@ -76,6 +76,7 @@ class SessionID;
 
 namespace WebCore {
 class CertificateInfo;
+struct Cookie;
 class CurlProxySettings;
 class DownloadID;
 class ProtectionSpace;
@@ -204,6 +205,11 @@ 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)>&&);
+    void setIgnoreCertificateErrors(PAL::SessionID, bool);
+
 #if ENABLE(RESOURCE_LOAD_STATISTICS)
     void clearPrevalentResource(PAL::SessionID, const RegistrableDomain&, CompletionHandler<void()>&&);
     void clearUserInteraction(PAL::SessionID, const RegistrableDomain&, CompletionHandler<void()>&&);
diff --git a/Source/WebKit/NetworkProcess/NetworkProcess.messages.in b/Source/WebKit/NetworkProcess/NetworkProcess.messages.in
index 08f07064a8e0ec85bacc0237ad428d57ff9abe7f..bc6691e51e27816be103a9c18341d067c1080fcf 100644
--- a/Source/WebKit/NetworkProcess/NetworkProcess.messages.in
+++ b/Source/WebKit/NetworkProcess/NetworkProcess.messages.in
@@ -82,6 +82,11 @@ messages -> NetworkProcess LegacyReceiver {
 
     PreconnectTo(PAL::SessionID sessionID, WebKit::WebPageProxyIdentifier webPageProxyID, WebCore::PageIdentifier webPageID, URL url, String userAgent, enum:uint8_t WebCore::StoredCredentialsPolicy storedCredentialsPolicy, enum:bool Optional<WebKit::NavigatingToAppBoundDomain> isNavigatingToAppBoundDomain);
 
+    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
+    SetIgnoreCertificateErrors(PAL::SessionID sessionID, bool ignoreTLSErrors)
+
 #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/NetworkSession.h b/Source/WebKit/NetworkProcess/NetworkSession.h
index d8d3ecbad8e688506a885640891848a2ba06e43a..62047204ac144fbcdeb5fd35dffa9956a26c43da 100644
--- a/Source/WebKit/NetworkProcess/NetworkSession.h
+++ b/Source/WebKit/NetworkProcess/NetworkSession.h
@@ -138,6 +138,9 @@ public:
 
     bool isStaleWhileRevalidateEnabled() const { return m_isStaleWhileRevalidateEnabled; }
 
+    void setIgnoreCertificateErrors(bool ignore) { m_ignoreCertificateErrors = ignore; }
+    bool ignoreCertificateErrors() { return m_ignoreCertificateErrors; }
+
 #if ENABLE(SERVICE_WORKER)
     void addSoftUpdateLoader(std::unique_ptr<ServiceWorkerSoftUpdateLoader>&& loader) { m_softUpdateLoaders.add(WTFMove(loader)); }
     void removeSoftUpdateLoader(ServiceWorkerSoftUpdateLoader* loader) { m_softUpdateLoaders.remove(loader); }
@@ -168,6 +171,7 @@ protected:
 #endif
     bool m_isStaleWhileRevalidateEnabled { false };
     UniqueRef<AdClickAttributionManager> m_adClickAttribution;
+    bool m_ignoreCertificateErrors { false };
 
     HashSet<Ref<NetworkResourceLoader>> m_keptAliveLoads;
 
diff --git a/Source/WebKit/NetworkProcess/NetworkSocketStream.cpp b/Source/WebKit/NetworkProcess/NetworkSocketStream.cpp
index d1fa427d82884fc43569d1bf0df7d728921502fc..30450ab01cddfcd406e46ac8e08ac50a2983f7a6 100644
--- a/Source/WebKit/NetworkProcess/NetworkSocketStream.cpp
+++ b/Source/WebKit/NetworkProcess/NetworkSocketStream.cpp
@@ -43,7 +43,7 @@ Ref<NetworkSocketStream> NetworkSocketStream::create(NetworkProcess& networkProc
 NetworkSocketStream::NetworkSocketStream(NetworkProcess& networkProcess, URL&& url, PAL::SessionID sessionID, const String& credentialPartition, WebSocketIdentifier identifier, IPC::Connection& connection, SourceApplicationAuditToken&& auditData)
     : m_identifier(identifier)
     , m_connection(connection)
-    , m_impl(SocketStreamHandleImpl::create(url, *this, sessionID, credentialPartition, WTFMove(auditData), NetworkStorageSessionProvider::create(networkProcess, sessionID).ptr()))
+    , m_impl(SocketStreamHandleImpl::create(url, networkProcess.networkSession(sessionID)->ignoreCertificateErrors(), *this, sessionID, credentialPartition, WTFMove(auditData), NetworkStorageSessionProvider::create(networkProcess, sessionID).ptr()))
 {
 }
 
diff --git a/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.mm b/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.mm
index 2e1d1cee66929cc11785c081afdf1e8c71f190bb..5c0aac805db6a2cb1425026b3febe0ba1d35b819 100644
--- a/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.mm
+++ b/Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.mm
@@ -657,7 +657,7 @@ static inline void processServerTrustEvaluation(NetworkSessionCocoa& session, Se
     NegotiatedLegacyTLS negotiatedLegacyTLS = NegotiatedLegacyTLS::No;
 
     if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
-        if (NetworkSessionCocoa::allowsSpecificHTTPSCertificateForHost(challenge))
+        if (sessionCocoa->ignoreCertificateErrors() || sessionCocoa->allowsSpecificHTTPSCertificateForHost(challenge))
             return completionHandler(NSURLSessionAuthChallengeUseCredential, [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust]);
 
 #if HAVE(TLS_PROTOCOL_VERSION_T)
diff --git a/Source/WebKit/NetworkProcess/curl/NetworkDataTaskCurl.cpp b/Source/WebKit/NetworkProcess/curl/NetworkDataTaskCurl.cpp
index 00e1a971b1b1e7b918bcde6d28794fbfab91d91c..e118f16b9a51bd5da6e4f393ba5faf695bac430f 100644
--- a/Source/WebKit/NetworkProcess/curl/NetworkDataTaskCurl.cpp
+++ b/Source/WebKit/NetworkProcess/curl/NetworkDataTaskCurl.cpp
@@ -26,9 +26,13 @@
 #include "config.h"
 #include "NetworkDataTaskCurl.h"
 
+#include "APIError.h"
 #include "AuthenticationChallengeDisposition.h"
 #include "AuthenticationManager.h"
+#include "DataReference.h"
+#include "Download.h"
 #include "NetworkSessionCurl.h"
+#include "NetworkProcess.h"
 #include <WebCore/AuthenticationChallenge.h>
 #include <WebCore/CookieJar.h>
 #include <WebCore/CurlRequest.h>
@@ -39,6 +43,8 @@
 #include <WebCore/SameSiteInfo.h>
 #include <WebCore/ShouldRelaxThirdPartyCookieBlocking.h>
 #include <WebCore/SynchronousLoaderClient.h>
+#include <WebCore/TextEncoding.h>
+#include <wtf/FileSystem.h>
 
 namespace WebKit {
 
@@ -81,6 +87,8 @@ NetworkDataTaskCurl::NetworkDataTaskCurl(NetworkSession& session, NetworkDataTas
         m_curlRequest->setUserPass(m_initialCredential.user(), m_initialCredential.password());
         m_curlRequest->setAuthenticationScheme(ProtectionSpaceAuthenticationSchemeHTTPBasic);
     }
+    if (m_session->ignoreCertificateErrors())
+        m_curlRequest->disableServerTrustEvaluation();
     m_curlRequest->setStartTime(m_startTime);
     m_curlRequest->start();
 }
@@ -187,7 +195,12 @@ void NetworkDataTaskCurl::curlDidReceiveBuffer(CurlRequest&, Ref<SharedBuffer>&&
     auto protectedThis = makeRef(*this);
     if (state() == State::Canceling || state() == State::Completed || (!m_client && !isDownload()))
         return;
-
+    if (isDownload()) {
+        FileSystem::PlatformFileHandle file = FileSystem::openFile(m_pendingDownloadLocation, FileSystem::FileOpenMode::Write);
+        FileSystem::writeToFile(file, buffer->data(), buffer->size());
+        FileSystem::closeFile(file);
+        return;
+    }
     m_client->didReceiveData(WTFMove(buffer));
 }
 
@@ -196,6 +209,12 @@ void NetworkDataTaskCurl::curlDidComplete(CurlRequest&, NetworkLoadMetrics&& net
     if (state() == State::Canceling || state() == State::Completed || (!m_client && !isDownload()))
         return;
 
+    if (isDownload()) {
+        auto* download = m_session->networkProcess().downloadManager().download(m_pendingDownloadID);
+        ASSERT(download);
+        download->didFinish();
+        return;
+    }
     m_client->didCompleteWithError({ }, WTFMove(networkLoadMetrics));
 }
 
@@ -209,6 +228,13 @@ void NetworkDataTaskCurl::curlDidFailWithError(CurlRequest& request, ResourceErr
         return;
     }
 
+    if (isDownload()) {
+        auto* download = m_session->networkProcess().downloadManager().download(m_pendingDownloadID);
+        ASSERT(download);
+        download->didFail(resourceError, IPC::DataReference());
+        return;
+    }
+
     m_client->didCompleteWithError(resourceError);
 }
 
@@ -245,6 +271,18 @@ void NetworkDataTaskCurl::invokeDidReceiveResponse()
             break;
         case PolicyAction::Ignore:
             break;
+        case PolicyAction::Download: {
+            FileSystem::deleteFile(m_pendingDownloadLocation);
+            auto& downloadManager = m_session->networkProcess().downloadManager();
+            auto download = makeUnique<Download>(downloadManager, m_pendingDownloadID, *this, *m_session, suggestedFilename());
+            auto* downloadPtr = download.get();
+            downloadManager.dataTaskBecameDownloadTask(m_pendingDownloadID, WTFMove(download));
+            downloadPtr->didCreateDestination(m_pendingDownloadLocation);
+
+            if (m_curlRequest)
+                m_curlRequest->completeDidReceiveResponse();
+            break;
+        }
         default:
             notImplemented();
             break;
@@ -327,6 +365,8 @@ void NetworkDataTaskCurl::willPerformHTTPRedirection()
             m_curlRequest->setUserPass(m_initialCredential.user(), m_initialCredential.password());
             m_curlRequest->setAuthenticationScheme(ProtectionSpaceAuthenticationSchemeHTTPBasic);
         }
+        if (m_session->ignoreCertificateErrors())
+            m_curlRequest->disableServerTrustEvaluation();
         m_curlRequest->setStartTime(m_startTime);
         m_curlRequest->start();
 
@@ -510,4 +550,16 @@ bool NetworkDataTaskCurl::isThirdPartyRequest(const WebCore::ResourceRequest& re
     return !WebCore::areRegistrableDomainsEqual(request.url(), request.firstPartyForCookies());
 }
 
+String NetworkDataTaskCurl::suggestedFilename() const
+{
+    if (!m_suggestedFilename.isEmpty())
+        return m_suggestedFilename;
+
+    String suggestedFilename = m_response.suggestedFilename();
+    if (!suggestedFilename.isEmpty())
+        return suggestedFilename;
+
+    return decodeURLEscapeSequences(m_response.url().lastPathComponent());
+}
+
 } // namespace WebKit
diff --git a/Source/WebKit/NetworkProcess/curl/NetworkDataTaskCurl.h b/Source/WebKit/NetworkProcess/curl/NetworkDataTaskCurl.h
index 04f081add9253f2296c026d9548f9b9a97c644f1..65db77501d4eb6dfbb46a4e5f26cae4389f57376 100644
--- a/Source/WebKit/NetworkProcess/curl/NetworkDataTaskCurl.h
+++ b/Source/WebKit/NetworkProcess/curl/NetworkDataTaskCurl.h
@@ -84,6 +84,7 @@ private:
 
     void appendCookieHeader(WebCore::ResourceRequest&);
     void handleCookieHeaders(const WebCore::ResourceRequest&, const WebCore::CurlResponse&);
+    String suggestedFilename() const override;
 
     bool isThirdPartyRequest(const WebCore::ResourceRequest&);
     bool shouldBlockCookies(const WebCore::ResourceRequest&);
diff --git a/Source/WebKit/NetworkProcess/soup/NetworkDataTaskSoup.cpp b/Source/WebKit/NetworkProcess/soup/NetworkDataTaskSoup.cpp
index 18a229c1a447148a79abefa88ae80cf53ecf5511..fef9fcd8c99cdddd584096ca73b6048de0f452d8 100644
--- a/Source/WebKit/NetworkProcess/soup/NetworkDataTaskSoup.cpp
+++ b/Source/WebKit/NetworkProcess/soup/NetworkDataTaskSoup.cpp
@@ -451,6 +451,8 @@ bool NetworkDataTaskSoup::tlsConnectionAcceptCertificate(GTlsCertificate* certif
 {
     ASSERT(m_soupRequest);
     URL url = soupURIToURL(soup_request_get_uri(m_soupRequest.get()));
+    if (m_session->ignoreCertificateErrors())
+        return true;
     auto error = SoupNetworkSession::checkTLSErrors(url, certificate, tlsErrors);
     if (!error)
         return true;
diff --git a/Source/WebKit/NetworkProcess/soup/NetworkSessionSoup.cpp b/Source/WebKit/NetworkProcess/soup/NetworkSessionSoup.cpp
index 407361f036e79891767d807fbb63c9044b260a70..24773d8f349d441e2b6b1981baa5af170a96b384 100644
--- a/Source/WebKit/NetworkProcess/soup/NetworkSessionSoup.cpp
+++ b/Source/WebKit/NetworkProcess/soup/NetworkSessionSoup.cpp
@@ -106,6 +106,11 @@ static gboolean webSocketAcceptCertificateCallback(GTlsConnection*, GTlsCertific
     return !SoupNetworkSession::checkTLSErrors(soupURIToURL(soup_message_get_uri(soupMessage)), certificate, errors);
 }
 
+static gboolean webSocketAcceptCertificateCallbackIgnoreTLSErrors(GTlsConnection*, GTlsCertificate* certificate, GTlsCertificateFlags errors, SoupMessage* soupMessage)
+{
+    return TRUE;
+}
+
 static void webSocketMessageNetworkEventCallback(SoupMessage* soupMessage, GSocketClientEvent event, GIOStream* connection)
 {
     if (event != G_SOCKET_CLIENT_TLS_HANDSHAKING)
@@ -114,6 +119,14 @@ static void webSocketMessageNetworkEventCallback(SoupMessage* soupMessage, GSock
     g_signal_connect(connection, "accept-certificate", G_CALLBACK(webSocketAcceptCertificateCallback), soupMessage);
 }
 
+static void webSocketMessageNetworkEventCallbackIgnoreTLSErrors(SoupMessage* soupMessage, GSocketClientEvent event, GIOStream* connection)
+{
+    if (event != G_SOCKET_CLIENT_TLS_HANDSHAKING)
+        return;
+
+    g_signal_connect(connection, "accept-certificate", G_CALLBACK(webSocketAcceptCertificateCallbackIgnoreTLSErrors), soupMessage);
+}
+
 std::unique_ptr<WebSocketTask> NetworkSessionSoup::createWebSocketTask(NetworkSocketChannel& channel, const ResourceRequest& request, const String& protocol)
 {
     GUniquePtr<SoupURI> soupURI = request.createSoupURI();
@@ -122,8 +135,12 @@ std::unique_ptr<WebSocketTask> NetworkSessionSoup::createWebSocketTask(NetworkSo
 
     GRefPtr<SoupMessage> soupMessage = adoptGRef(soup_message_new_from_uri(SOUP_METHOD_GET, soupURI.get()));
     request.updateSoupMessage(soupMessage.get(), blobRegistry());
-    if (request.url().protocolIs("wss"))
-        g_signal_connect(soupMessage.get(), "network-event", G_CALLBACK(webSocketMessageNetworkEventCallback), nullptr);
+    if (request.url().protocolIs("wss")) {
+        if (ignoreCertificateErrors())
+          g_signal_connect(soupMessage.get(), "network-event", G_CALLBACK(webSocketMessageNetworkEventCallbackIgnoreTLSErrors), nullptr);
+        else
+          g_signal_connect(soupMessage.get(), "network-event", G_CALLBACK(webSocketMessageNetworkEventCallback), nullptr);
+    }
     return makeUnique<WebSocketTask>(channel, soupSession(), soupMessage.get(), protocol);
 }
 
diff --git a/Source/WebKit/PlatformGTK.cmake b/Source/WebKit/PlatformGTK.cmake
index f0b639b5bce1a2f74a14ce89b0bcbb819c2e3974..437fcb91fe4933e5c44d67b1c5c1060148eba357 100644
--- a/Source/WebKit/PlatformGTK.cmake
+++ b/Source/WebKit/PlatformGTK.cmake
@@ -447,6 +447,9 @@ list(APPEND WebKit_SYSTEM_INCLUDE_DIRECTORIES
     ${GSTREAMER_PBUTILS_INCLUDE_DIRS}
     ${GTK_INCLUDE_DIRS}
     ${LIBSOUP_INCLUDE_DIRS}
+# Playwright begin
+    ${LIBVPX_INCLUDE_DIRS}
+# Playwright end
 )
 
 if (USE_WPE_RENDERER)
@@ -500,6 +503,9 @@ if (USE_LIBWEBRTC)
     list(APPEND WebKit_SYSTEM_INCLUDE_DIRECTORIES
         "${THIRDPARTY_DIR}/libwebrtc/Source/"
         "${THIRDPARTY_DIR}/libwebrtc/Source/webrtc"
+# Playwright begin
+        "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/include"
+# Playwright end
     )
 endif ()
 
diff --git a/Source/WebKit/PlatformWPE.cmake b/Source/WebKit/PlatformWPE.cmake
index 89cc7e3cdb233ccaf2eb1c026f42394cc714498b..54a5a7bd2e115206af3ca3caff0aea9a6b399890 100644
--- a/Source/WebKit/PlatformWPE.cmake
+++ b/Source/WebKit/PlatformWPE.cmake
@@ -256,6 +256,7 @@ 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"
@@ -286,8 +287,52 @@ list(APPEND WebKit_SYSTEM_INCLUDE_DIRECTORIES
     ${GSTREAMER_VIDEO_INCLUDE_DIRS}
     ${LIBSECCOMP_INCLUDE_DIRS}
     ${LIBSOUP_INCLUDE_DIRS}
+# Playwright begin
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/include"
+# Playwright end
 )
 
+# Playwright begin
+list(APPEND WebKit_SOURCES
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/compare.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/compare_common.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/compare_gcc.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/convert.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/convert_argb.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/convert_from.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/convert_from_argb.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/convert_jpeg.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/convert_to_argb.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/convert_to_i420.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/cpu_id.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/mjpeg_decoder.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/mjpeg_validate.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/planar_functions.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/compare_neon.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/compare_neon64.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/rotate.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/rotate_any.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/rotate_argb.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/rotate_common.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/rotate_gcc.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/rotate_neon.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/rotate_neon64.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/row_any.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/row_common.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/row_gcc.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/row_neon.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/row_neon64.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/scale.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/scale_any.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/scale_argb.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/scale_common.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/scale_gcc.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/scale_neon.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/scale_neon64.cc"
+    "${THIRDPARTY_DIR}/libwebrtc/Source/third_party/libyuv/source/video_common.cc"
+)
+# Playwright end
+
 list(APPEND WebKit_LIBRARIES
     Cairo::Cairo
     Freetype::Freetype
diff --git a/Source/WebKit/PlatformWin.cmake b/Source/WebKit/PlatformWin.cmake
index 3b94f4dba2c3b9659a1269bfe030d5d010b5b1bd..43dde2ab5a5b925ac6916656d8528b0e172fc564 100644
--- a/Source/WebKit/PlatformWin.cmake
+++ b/Source/WebKit/PlatformWin.cmake
@@ -59,8 +59,12 @@ list(APPEND WebKit_SOURCES
 
     UIProcess/WebsiteData/win/WebsiteDataStoreWin.cpp
 
+    UIProcess/win/InspectorTargetProxyWin.cpp
+    UIProcess/win/InspectorPlaywrightAgentClientWin.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 bf64299025afcc1cb784d35dd3ea611d47018b12..5e1e045d1b0dfb327c658e432ebf3a6f8b38ff27 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;
@@ -71,19 +72,35 @@ 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&);
     NativeWebKeyboardEvent(GdkEvent*, const String&, Vector<String>&& commands);
     NativeWebKeyboardEvent(const String&, Optional<Vector<WebCore::CompositionUnderline>>&&, Optional<EditingRange>&&);
     NativeWebKeyboardEvent(Type, const String& text, const String& key, const String& code, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, Vector<String>&& commands, bool isKeypad, OptionSet<Modifier>);
+    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 d6f9902b963bd9a0036a6008d719c3e5b15402c4..8a23efeab7125f86d3b990bb09921ecdbbaaa205 100644
--- a/Source/WebKit/Shared/NativeWebMouseEvent.h
+++ b/Source/WebKit/Shared/NativeWebMouseEvent.h
@@ -77,6 +77,11 @@ 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/WebCoreArgumentCoders.cpp b/Source/WebKit/Shared/WebCoreArgumentCoders.cpp
index 5447fca763528a4e99b433e4dfeb8dbf544175f3..2f5aafebfd2dacf061203ca7675258d112746462 100644
--- a/Source/WebKit/Shared/WebCoreArgumentCoders.cpp
+++ b/Source/WebKit/Shared/WebCoreArgumentCoders.cpp
@@ -1495,6 +1495,9 @@ void ArgumentCoder<WindowFeatures>::encode(Encoder& encoder, const WindowFeature
     encoder << windowFeatures.resizable;
     encoder << windowFeatures.fullscreen;
     encoder << windowFeatures.dialog;
+    encoder << windowFeatures.noopener;
+    encoder << windowFeatures.noreferrer;
+    encoder << windowFeatures.additionalFeatures;
 }
 
 bool ArgumentCoder<WindowFeatures>::decode(Decoder& decoder, WindowFeatures& windowFeatures)
@@ -1523,6 +1526,12 @@ bool ArgumentCoder<WindowFeatures>::decode(Decoder& decoder, WindowFeatures& win
         return false;
     if (!decoder.decode(windowFeatures.dialog))
         return false;
+    if (!decoder.decode(windowFeatures.noopener))
+        return false;
+    if (!decoder.decode(windowFeatures.noreferrer))
+        return false;
+    if (!decoder.decode(windowFeatures.additionalFeatures))
+        return false;
     return true;
 }
 
diff --git a/Source/WebKit/Shared/WebEvent.h b/Source/WebKit/Shared/WebEvent.h
index 4bddad03dc933d8727c5e2fb6cda90d5a5e0b15d..a346623a30b3a7b15669f6e07b0a56c602b80e0d 100644
--- a/Source/WebKit/Shared/WebEvent.h
+++ b/Source/WebKit/Shared/WebEvent.h
@@ -38,6 +38,7 @@
 #include <WebCore/KeypressCommand.h>
 #include <wtf/EnumTraits.h>
 #include <wtf/OptionSet.h>
+#include <wtf/RefCounted.h>
 #include <wtf/WallTime.h>
 #include <wtf/text/WTFString.h>
 
@@ -253,14 +254,18 @@ 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; }
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 e18736f7e372d56c06c030af8a175473bce90baf..214bf11d368d372afbc330875abc4b9764121b4a 100644
--- a/Source/WebKit/Shared/WebPageCreationParameters.cpp
+++ b/Source/WebKit/Shared/WebPageCreationParameters.cpp
@@ -147,6 +147,8 @@ void WebPageCreationParameters::encode(IPC::Encoder& encoder) const
     encoder << crossOriginAccessControlCheckEnabled;
     encoder << processDisplayName;
 
+    encoder << shouldPauseInInspectorWhenShown;
+
     encoder << shouldCaptureAudioInUIProcess;
     encoder << shouldCaptureAudioInGPUProcess;
     encoder << shouldCaptureVideoInUIProcess;
@@ -472,7 +474,10 @@ Optional<WebPageCreationParameters> WebPageCreationParameters::decode(IPC::Decod
     if (!processDisplayName)
         return WTF::nullopt;
     parameters.processDisplayName = WTFMove(*processDisplayName);
-    
+
+    if (!decoder.decode(parameters.shouldPauseInInspectorWhenShown))
+        return WTF::nullopt;
+
     if (!decoder.decode(parameters.shouldCaptureAudioInUIProcess))
         return WTF::nullopt;
 
@@ -493,13 +498,13 @@ Optional<WebPageCreationParameters> WebPageCreationParameters::decode(IPC::Decod
 
     if (!decoder.decode(parameters.needsInAppBrowserPrivacyQuirks))
         return WTF::nullopt;
-    
+
     if (!decoder.decode(parameters.limitsNavigationsToAppBoundDomains))
         return WTF::nullopt;
     
     if (!decoder.decode(parameters.shouldRelaxThirdPartyCookieBlocking))
         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 992baf499b84f7558c9983f485ec235d099f9ae3..c34c64c4ff6ceafdfb8fc8882a3eb3da6ed8c8e3 100644
--- a/Source/WebKit/Shared/WebPageCreationParameters.h
+++ b/Source/WebKit/Shared/WebPageCreationParameters.h
@@ -230,6 +230,8 @@ struct WebPageCreationParameters {
     bool limitsNavigationsToAppBoundDomains { false };
     WebCore::ShouldRelaxThirdPartyCookieBlocking shouldRelaxThirdPartyCookieBlocking { WebCore::ShouldRelaxThirdPartyCookieBlocking::No };
 
+    bool shouldPauseInInspectorWhenShown { false };
+
 #if PLATFORM(GTK)
     String themeName;
 #endif
diff --git a/Source/WebKit/Shared/WebPreferences.yaml b/Source/WebKit/Shared/WebPreferences.yaml
index fad1a9f588621e95e19b1a4fe74ea3023642413d..bf92a79662687f2bf1070ad599cf30e6244b19ae 100644
--- a/Source/WebKit/Shared/WebPreferences.yaml
+++ b/Source/WebKit/Shared/WebPreferences.yaml
@@ -317,7 +317,7 @@ MediaControlsScaleWithPageZoom:
 
 InspectorStartsAttached:
   type: bool
-  defaultValue: true
+  defaultValue: false
   webcoreBinding: none
 
 ShowsToolTipOverTruncatedText:
diff --git a/Source/WebKit/Shared/gtk/NativeWebKeyboardEventGtk.cpp b/Source/WebKit/Shared/gtk/NativeWebKeyboardEventGtk.cpp
index c76a9e1f7dae7a31c4048d8f00d849a18ebaff23..1cfd9c7acb69dea69783c42b3f427929509782a4 100644
--- a/Source/WebKit/Shared/gtk/NativeWebKeyboardEventGtk.cpp
+++ b/Source/WebKit/Shared/gtk/NativeWebKeyboardEventGtk.cpp
@@ -50,7 +50,7 @@ NativeWebKeyboardEvent::NativeWebKeyboardEvent(Type type, const String& text, co
 }
 
 NativeWebKeyboardEvent::NativeWebKeyboardEvent(const NativeWebKeyboardEvent& event)
-    : WebKeyboardEvent(event.type(), event.text(), event.key(), event.code(), event.keyIdentifier(), event.windowsVirtualKeyCode(), event.nativeVirtualKeyCode(), event.handledByInputMethod(), Optional<Vector<WebCore::CompositionUnderline>>(event.preeditUnderlines()), Optional<EditingRange>(event.preeditSelectionRange()), Vector<String>(event.commands()), event.isKeypad(), event.modifiers(), event.timestamp())
+    : WebKeyboardEvent(event)
     , m_nativeEvent(event.nativeEvent() ? gdk_event_copy(event.nativeEvent()) : nullptr)
 {
 }
diff --git a/Source/WebKit/Shared/gtk/NativeWebMouseEventGtk.cpp b/Source/WebKit/Shared/gtk/NativeWebMouseEventGtk.cpp
index 66fcf27bcdd78e9c4d2b73e1e05830575bc9c05d..656c79494d4224b958ce338c5ebe0f0bfb8d8977 100644
--- a/Source/WebKit/Shared/gtk/NativeWebMouseEventGtk.cpp
+++ b/Source/WebKit/Shared/gtk/NativeWebMouseEventGtk.cpp
@@ -54,7 +54,7 @@ NativeWebMouseEvent::NativeWebMouseEvent(Type type, Button button, unsigned shor
 }
 
 NativeWebMouseEvent::NativeWebMouseEvent(const NativeWebMouseEvent& event)
-    : WebMouseEvent(event.type(), event.button(), event.buttons(), event.position(), event.globalPosition(), event.deltaX(), event.deltaY(), event.deltaZ(), event.clickCount(), event.modifiers(), event.timestamp())
+    : WebMouseEvent(event)
     , m_nativeEvent(event.nativeEvent() ? gdk_event_copy(const_cast<GdkEvent*>(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 5d620b1ad03924b3ffd81d95105d4bf14341d9d4..f87f3a829cea0ab7c9a97e7b04aabe831cfdaa87 100644
--- a/Source/WebKit/Sources.txt
+++ b/Source/WebKit/Sources.txt
@@ -274,16 +274,20 @@ Shared/WebsiteData/WebsiteData.cpp
 
 UIProcess/AuxiliaryProcessProxy.cpp
 UIProcess/BackgroundProcessResponsivenessTimer.cpp
+UIProcess/BrowserInspectorPipe.cpp
 UIProcess/DeviceIdHashSaltStorage.cpp
 UIProcess/DrawingAreaProxy.cpp
 UIProcess/FrameLoadState.cpp
 UIProcess/GeolocationPermissionRequestManagerProxy.cpp
 UIProcess/GeolocationPermissionRequestProxy.cpp
+UIProcess/InspectorDialogAgent.cpp
+UIProcess/InspectorPlaywrightAgent.cpp
 UIProcess/LegacyGlobalSettings.cpp
 UIProcess/PageLoadState.cpp
 UIProcess/ProcessAssertion.cpp
 UIProcess/ProcessThrottler.cpp
 UIProcess/ProvisionalPageProxy.cpp
+UIProcess/RemoteInspectorPipe.cpp
 UIProcess/ResponsivenessTimer.cpp
 UIProcess/SuspendedPageProxy.cpp
 UIProcess/SystemPreviewController.cpp
@@ -320,6 +324,8 @@ 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
@@ -439,6 +445,7 @@ UIProcess/Inspector/WebPageDebuggable.cpp
 UIProcess/Inspector/WebPageInspectorController.cpp
 
 UIProcess/Inspector/Agents/InspectorBrowserAgent.cpp
+UIProcess/Inspector/Agents/InspectorScreencastAgent.cpp
 
 UIProcess/Media/AudioSessionRoutingArbitratorProxy.cpp
 UIProcess/Media/MediaUsageManager.cpp
diff --git a/Source/WebKit/SourcesCocoa.txt b/Source/WebKit/SourcesCocoa.txt
index 2519b7ee283a4015acc2a434011d859c4a2c687e..dc10ea6013e5c3a92e3f4d3eb8bbe842f257a44f 100644
--- a/Source/WebKit/SourcesCocoa.txt
+++ b/Source/WebKit/SourcesCocoa.txt
@@ -251,6 +251,7 @@ 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
@@ -411,6 +412,7 @@ UIProcess/Inspector/Cocoa/InspectorDelegate.mm
 UIProcess/Inspector/ios/WKInspectorHighlightView.mm
 UIProcess/Inspector/ios/WKInspectorNodeSearchGestureRecognizer.mm
 
+UIProcess/Inspector/mac/InspectorScreencastAgentMac.mm
 UIProcess/Inspector/mac/RemoteWebInspectorProxyMac.mm
 UIProcess/Inspector/mac/WebInspectorProxyMac.mm
 UIProcess/Inspector/mac/WKInspectorViewController.mm
diff --git a/Source/WebKit/SourcesGTK.txt b/Source/WebKit/SourcesGTK.txt
index 54f8fa408048aad78529a58f774963b220b7c56a..53dba1ff30d0ffb01504909ee77778f6345a4a32 100644
--- a/Source/WebKit/SourcesGTK.txt
+++ b/Source/WebKit/SourcesGTK.txt
@@ -135,6 +135,7 @@ 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
@@ -230,6 +231,7 @@ UIProcess/geoclue/GeoclueGeolocationProvider.cpp
 
 UIProcess/Inspector/glib/RemoteInspectorClient.cpp
 
+UIProcess/Inspector/Agents/ScreencastEncoder.cpp
 UIProcess/Inspector/gtk/RemoteWebInspectorProxyGtk.cpp
 UIProcess/Inspector/gtk/WebInspectorProxyGtk.cpp
 UIProcess/Inspector/gtk/WebKitInspectorWindow.cpp
@@ -250,6 +252,7 @@ UIProcess/WebsiteData/unix/WebsiteDataStoreUnix.cpp
 
 UIProcess/cairo/BackingStoreCairo.cpp @no-unify
 
+UIProcess/glib/InspectorPlaywrightAgentClientGLib.cpp
 UIProcess/glib/WebProcessPoolGLib.cpp
 UIProcess/glib/WebProcessProxyGLib.cpp
 UIProcess/glib/WebsiteDataStoreGLib.cpp @no-unify
@@ -265,6 +268,7 @@ UIProcess/gtk/ClipboardGtk3.cpp @no-unify
 UIProcess/gtk/ClipboardGtk4.cpp @no-unify
 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
@@ -275,6 +279,8 @@ 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 fbceb00524e7b399dce747e73efc42d0bdc34c8c..e0fc5d0580589d346cdeddbb673fb08a148e50b1 100644
--- a/Source/WebKit/SourcesWPE.txt
+++ b/Source/WebKit/SourcesWPE.txt
@@ -125,6 +125,7 @@ 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
@@ -201,7 +202,8 @@ UIProcess/Automation/wpe/WebAutomationSessionWPE.cpp
 UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.cpp
 
 UIProcess/geoclue/GeoclueGeolocationProvider.cpp
-
+UIProcess/Inspector/Agents/ScreencastEncoder.cpp
+UIProcess/glib/InspectorPlaywrightAgentClientGLib.cpp
 UIProcess/glib/WebProcessPoolGLib.cpp
 UIProcess/glib/WebProcessProxyGLib.cpp
 UIProcess/glib/WebsiteDataStoreGLib.cpp @no-unify
@@ -226,6 +228,10 @@ UIProcess/linux/MemoryPressureMonitor.cpp
 UIProcess/soup/WebCookieManagerProxySoup.cpp
 UIProcess/soup/WebProcessPoolSoup.cpp
 
+UIProcess/wpe/InspectorTargetProxyWPE.cpp
+UIProcess/wpe/WebPageInspectorEmulationAgentWPE.cpp
+UIProcess/wpe/WebPageInspectorInputAgentWPE.cpp
+
 UIProcess/wpe/WebPageProxyWPE.cpp
 
 WebProcess/GPU/media/gstreamer/VideoLayerRemoteGStreamer.cpp
diff --git a/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.cpp b/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.cpp
index 7227587e55153e3d8a13386dedd07de9a5d498be..c870126fc1ccd4cebe6b7a51074f489c83592c28 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_shouldCaptureDisplayInUIProcess = this->m_shouldCaptureDisplayInUIProcess;
diff --git a/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.h b/Source/WebKit/UIProcess/API/APIProcessPoolConfiguration.h
index 41ed3857db50b2944c78933f22b5acdb84ddaf3d..f1105988b2b0ccf3e8a87f7d0ed5504be84226b4 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; }
 
@@ -160,6 +165,9 @@ 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_shouldCaptureDisplayInUIProcess { DEFAULT_CAPTURE_DISPLAY_IN_UI_PROCESS };
diff --git a/Source/WebKit/UIProcess/API/APIUIClient.h b/Source/WebKit/UIProcess/API/APIUIClient.h
index 2e5be65bdfdccb888915d08df86abda741aadcb5..2da7443b8365431d2640ec54a816435986e285d3 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*, WebKit::FrameInfoData&&, Function<void()>&& completionHandler) { completionHandler(); }
     virtual void runJavaScriptConfirm(WebKit::WebPageProxy&, const WTF::String&, WebKit::WebFrameProxy*, WebKit::FrameInfoData&&, Function<void(bool)>&& completionHandler) { completionHandler(false); }
     virtual void runJavaScriptPrompt(WebKit::WebPageProxy&, const WTF::String&, const WTF::String&, WebKit::WebFrameProxy*, WebKit::FrameInfoData&&, 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 8fb8e096d466e2361cdb5203efc9c568c9e69511..ed082f4af22e7f5c6942e8cd8fcc3e24b3883623 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..450033d87fefb743ab7240ce317fae221f91dcf5 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 "InspectorPlaywrightAgentClientWin.h"
+#endif
+
 #include "WKAPICast.h"
 #include "WebInspectorProxy.h"
 #include "WebPageProxy.h"
@@ -130,4 +135,11 @@ void WKInspectorToggleElementSelection(WKInspectorRef inspectorRef)
     toImpl(inspectorRef)->toggleElementSelection();
 }
 
+void WKInspectorInitializeRemoteInspectorPipe(ConfigureDataStoreCallback configureDataStore, CreatePageCallback createPage, QuitCallback quit)
+{
+#if PLATFORM(WIN)
+    initializeBrowserInspectorPipe(makeUnique<InspectorPlaywrightAgentClientWin>(configureDataStore, 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..edd6e5cae033124c589959a42522fde07a42fdf6 100644
--- a/Source/WebKit/UIProcess/API/C/WKInspector.h
+++ b/Source/WebKit/UIProcess/API/C/WKInspector.h
@@ -66,6 +66,10 @@ WK_EXPORT void WKInspectorTogglePageProfiling(WKInspectorRef inspector);
 WK_EXPORT bool WKInspectorIsElementSelectionActive(WKInspectorRef inspector);
 WK_EXPORT void WKInspectorToggleElementSelection(WKInspectorRef inspector);
 
+typedef void (*ConfigureDataStoreCallback)(WKWebsiteDataStoreRef dataStore);
+typedef WKPageRef (*CreatePageCallback)(WKPageConfigurationRef configuration);
+typedef void (*QuitCallback)();
+WK_EXPORT void WKInspectorInitializeRemoteInspectorPipe(ConfigureDataStoreCallback, CreatePageCallback, QuitCallback);
 #ifdef __cplusplus
 }
 #endif
diff --git a/Source/WebKit/UIProcess/API/C/WKPage.cpp b/Source/WebKit/UIProcess/API/C/WKPage.cpp
index ba2feecd2885acc45dd153ff502d49f7650f2c6d..9c4bb27242bfa23a91122d899200a1f1ce151fdb 100644
--- a/Source/WebKit/UIProcess/API/C/WKPage.cpp
+++ b/Source/WebKit/UIProcess/API/C/WKPage.cpp
@@ -1689,6 +1689,13 @@ 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)
@@ -1749,6 +1756,8 @@ 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/C/WKWebsiteDataStoreRef.cpp b/Source/WebKit/UIProcess/API/C/WKWebsiteDataStoreRef.cpp
index be5030797402d00ba0e0bc371e52c8c1d47b1ca1..c9765685d5197b87a26371bf50f55122340f1bd3 100644
--- a/Source/WebKit/UIProcess/API/C/WKWebsiteDataStoreRef.cpp
+++ b/Source/WebKit/UIProcess/API/C/WKWebsiteDataStoreRef.cpp
@@ -633,7 +633,7 @@ void WKWebsiteDataStoreSetResourceLoadStatisticsToSameSiteStrictCookiesForTestin
 void WKWebsiteDataStoreSetAppBoundDomainsForTesting(WKArrayRef originURLsRef, void* context, WKWebsiteDataStoreSetAppBoundDomainsForTestingFunction completionHandler)
 {
 #if PLATFORM(COCOA)
-    RefPtr<API::Array> originURLsArray = toImpl(originURLsRef);
+    RefPtr<API::Array> originURLsArray = WebKit::toImpl(originURLsRef);
     size_t newSize = originURLsArray ? originURLsArray->size() : 0;
     HashSet<WebCore::RegistrableDomain> domains;
     domains.reserveInitialCapacity(newSize);
diff --git a/Source/WebKit/UIProcess/API/Cocoa/WKProcessPool.mm b/Source/WebKit/UIProcess/API/Cocoa/WKProcessPool.mm
index 7b9469ee130d1b62c8b8187bd25748b42c40a352..dab2ff1ebaa7a9c13efe5ae75779f1c8efe19fc0 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>
@@ -85,6 +86,18 @@ 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 c0a84a1bfcfba85455988d20a18d381eb273f6da..513868305c4c1884b7effdd09e25fb6b79c0664f 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/WKProcessPoolPrivate.h
+++ b/Source/WebKit/UIProcess/API/Cocoa/WKProcessPoolPrivate.h
@@ -38,6 +38,7 @@
 
 @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 591428f7f579e76ff01bc94b83f5994af8e48e00..03fc6cf2d3074d9227d7815ac5c72fdb33e8a694 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..5fabe06a3289689246c36dfd96eb9900a48b2b0f
--- /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:(NSString *)proxyServer WithBypassList:(NSString *)proxyBypassList;
+- (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..e7143513ea2be8e1cdab5c86a28643fffea626dd
--- /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 "InspectorPlaywrightAgentClientMac.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<InspectorPlaywrightAgentClientMac>(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 df2b919c9ba18cc9cc0471a4334eb85c45e3820e..b5a73c8d6863217da0edb97688d17a7debab3c11 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 9c6aa9a080acd3e9e3a4a744141bb5caab9504ba..27f385dd1e823cd59b16d3df6e7bea2742092719 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/_WKProcessPoolConfiguration.mm
+++ b/Source/WebKit/UIProcess/API/Cocoa/_WKProcessPoolConfiguration.mm
@@ -231,6 +231,16 @@
     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 66bf24df826daa8e7284248fd1b728cb5ebff343..d40f4f4be2bf76fa300cb54a06e81ff5a1e18d16 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..c7f51f06dcbc233aef69d9d8b6bf91e70e817096
--- /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 "InspectorPlaywrightAgentClientGLib.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, const char* defaultProxyURI, const char* const* ignoreHosts)
+{
+#if ENABLE(REMOTE_INSPECTOR)
+    WebKit::initializeBrowserInspectorPipe(makeUnique<WebKit::InspectorPlaywrightAgentClientGlib>(mainLoop, defaultProxyURI, ignoreHosts));
+#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 2ceb2b4f49f409bbe6e6810115e36d0c84f83b5d..16d2062b746b80ace6f39d779e9c3b8796b581b1 100644
--- a/Source/WebKit/UIProcess/API/glib/WebKitUIClient.cpp
+++ b/Source/WebKit/UIProcess/API/glib/WebKitUIClient.cpp
@@ -93,6 +93,10 @@ 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 041bfb545c6af6220a8266d356ac19d90791cb83..265a84c7e6f0dc494182d859d2db4b91addb3023 100644
--- a/Source/WebKit/UIProcess/API/glib/WebKitWebContext.cpp
+++ b/Source/WebKit/UIProcess/API/glib/WebKitWebContext.cpp
@@ -119,8 +119,8 @@ enum {
     PROP_LOCAL_STORAGE_DIRECTORY,
 #endif
     PROP_WEBSITE_DATA_MANAGER,
-#if PLATFORM(GTK)
     PROP_PSON_ENABLED,
+#if PLATFORM(GTK)
 #if !USE(GTK4)
     PROP_USE_SYSYEM_APPEARANCE_FOR_SCROLLBARS
 #endif
@@ -205,8 +205,8 @@ struct _WebKitWebContextPrivate {
 
     RefPtr<WebProcessPool> processPool;
     bool clientsDetached;
-#if PLATFORM(GTK)
     bool psonEnabled;
+#if PLATFORM(GTK)
 #if !USE(GTK4)
     bool useSystemAppearanceForScrollbars;
 #endif
@@ -306,11 +306,9 @@ WEBKIT_DEFINE_TYPE(WebKitWebContext, webkit_web_context, G_TYPE_OBJECT)
 
 static const char* injectedBundleDirectory()
 {
-#if ENABLE(DEVELOPER_MODE)
     const char* bundleDirectory = g_getenv("WEBKIT_INJECTED_BUNDLE_PATH");
     if (bundleDirectory && g_file_test(bundleDirectory, G_FILE_TEST_IS_DIR))
         return bundleDirectory;
-#endif
 
 #if PLATFORM(GTK)
     static const char* injectedBundlePath = LIBDIR G_DIR_SEPARATOR_S "webkit2gtk-" WEBKITGTK_API_VERSION_STRING
@@ -335,10 +333,10 @@ 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;
+#if PLATFORM(GTK)
 #if !USE(GTK4)
     case PROP_USE_SYSYEM_APPEARANCE_FOR_SCROLLBARS:
         g_value_set_boolean(value, webkit_web_context_get_use_system_appearance_for_scrollbars(context));
@@ -365,10 +363,10 @@ 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;
+#if PLATFORM(GTK)
 #if !USE(GTK4)
     case PROP_USE_SYSYEM_APPEARANCE_FOR_SCROLLBARS:
         webkit_web_context_set_use_system_appearance_for_scrollbars(context, g_value_get_boolean(value));
@@ -380,10 +378,19 @@ static void webkitWebContextSetProperty(GObject* object, guint propID, const GVa
     }
 }
 
+static int webkitWebContext = 0;
+
+int webkitWebContextExistingCount()
+{
+    return webkitWebContext;
+}
+
 static void webkitWebContextConstructed(GObject* object)
 {
     G_OBJECT_CLASS(webkit_web_context_parent_class)->constructed(object);
 
+    ++webkitWebContext;
+
     GUniquePtr<char> bundleFilename(g_build_filename(injectedBundleDirectory(), INJECTED_BUNDLE_FILENAME, nullptr));
 
     WebKitWebContext* webContext = WEBKIT_WEB_CONTEXT(object);
@@ -391,8 +398,8 @@ static void webkitWebContextConstructed(GObject* object)
 
     API::ProcessPoolConfiguration configuration;
     configuration.setInjectedBundlePath(FileSystem::stringFromFileSystemRepresentation(bundleFilename.get()));
-#if PLATFORM(GTK)
     configuration.setProcessSwapsOnNavigation(priv->psonEnabled);
+#if PLATFORM(GTK)
 #if !USE(GTK4)
     configuration.setUseSystemAppearanceForScrollbars(priv->useSystemAppearanceForScrollbars);
 #endif
@@ -404,6 +411,11 @@ static void webkitWebContextConstructed(GObject* object)
     if (!webkit_website_data_manager_is_ephemeral(priv->websiteDataManager.get()))
         configuration.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) {
@@ -438,6 +450,8 @@ static void webkitWebContextConstructed(GObject* object)
 
 static void webkitWebContextDispose(GObject* object)
 {
+    --webkitWebContext;
+
     WebKitWebContextPrivate* priv = WEBKIT_WEB_CONTEXT(object)->priv;
     if (!priv->clientsDetached) {
         priv->clientsDetached = true;
@@ -515,7 +529,6 @@ 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:
      *
@@ -539,6 +552,7 @@ static void webkit_web_context_class_init(WebKitWebContextClass* webContextClass
             FALSE,
             static_cast<GParamFlags>(WEBKIT_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY)));
 
+#if PLATFORM(GTK)
 #if !USE(GTK4)
     /**
      * WebKitWebContext:use-system-appearance-for-scrollbars:
diff --git a/Source/WebKit/UIProcess/API/glib/WebKitWebContextPrivate.h b/Source/WebKit/UIProcess/API/glib/WebKitWebContextPrivate.h
index d8569c859babfe1169c682eb686366e3d069b9ad..779802f0fe22e151783d9277d7ee5af02d5ec952 100644
--- a/Source/WebKit/UIProcess/API/glib/WebKitWebContextPrivate.h
+++ b/Source/WebKit/UIProcess/API/glib/WebKitWebContextPrivate.h
@@ -44,3 +44,4 @@ void webkitWebContextInitializeNotificationPermissions(WebKitWebContext*);
 #if ENABLE(REMOTE_INSPECTOR)
 void webkitWebContextWillCloseAutomationSession(WebKitWebContext*);
 #endif
+int webkitWebContextExistingCount();
diff --git a/Source/WebKit/UIProcess/API/glib/WebKitWebView.cpp b/Source/WebKit/UIProcess/API/glib/WebKitWebView.cpp
index 50df3f448a7d38e3282e66282490f170feebaaed..c7161970015b26eac248c01b77f977a871d4a491 100644
--- a/Source/WebKit/UIProcess/API/glib/WebKitWebView.cpp
+++ b/Source/WebKit/UIProcess/API/glib/WebKitWebView.cpp
@@ -31,6 +31,7 @@
 #include "WebCertificateInfo.h"
 #include "WebContextMenuItem.h"
 #include "WebContextMenuItemData.h"
+#include "WebPageInspectorController.h"
 #include "WebKitAuthenticationRequestPrivate.h"
 #include "WebKitBackForwardListPrivate.h"
 #include "WebKitContextMenuClient.h"
@@ -131,6 +132,7 @@ enum {
     CLOSE,
 
     SCRIPT_DIALOG,
+    SCRIPT_DIALOG_HANDLED,
 
     DECIDE_POLICY,
     PERMISSION_REQUEST,
@@ -432,6 +434,9 @@ void WebKitWebViewClient::handleDownloadRequest(WKWPE::View&, DownloadProxy& dow
 
 void WebKitWebViewClient::frameDisplayed(WKWPE::View&)
 {
+    if (RefPtr<cairo_surface_t> surface = adoptRef(webkitWebViewBackendTakeScreenshot(m_webView->priv->backend.get())))
+        getPage(m_webView).inspectorController().didPaint(surface.get());
+
     {
         SetForScope<bool> inFrameDisplayedGuard(m_webView->priv->inFrameDisplayed, true);
         for (const auto& callback : m_webView->priv->frameDisplayedCallbacks) {
@@ -462,6 +467,7 @@ void WebKitWebViewClient::didReceiveUserMessage(WKWPE::View&, UserMessage&& mess
 {
     webkitWebViewDidReceiveUserMessage(m_webView, WTFMove(message), WTFMove(completionHandler));
 }
+
 #endif
 
 static gboolean webkitWebViewLoadFail(WebKitWebView* webView, WebKitLoadEvent, const char* failingURI, GError* error)
@@ -1561,6 +1567,15 @@ 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
@@ -2441,6 +2456,23 @@ 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;
+#if PLATFORM(WPE)
+    dialog->isUserHandled = false;
+#endif
+    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 b9e56fc55fd7dfa821f789264b0c15f9b4c7b412..4138d5b42077f735264ac7a168cce329ebaa89c3 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 0aee4bc9380cb47ca4900d8556d51e24d8f14be7..82d1d747a224141e9f006c634b7bfac2f89e5ed0 100644
--- a/Source/WebKit/UIProcess/API/gtk/PageClientImpl.cpp
+++ b/Source/WebKit/UIProcess/API/gtk/PageClientImpl.cpp
@@ -241,6 +241,8 @@ void PageClientImpl::doneWithKeyEvent(const NativeWebKeyboardEvent& event, bool
 {
     if (wasEventHandled || event.type() != WebEvent::Type::KeyDown || !event.nativeEvent())
         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..1044d9b4df51acb52fb7ee03456b5a64ef7039a8
--- /dev/null
+++ b/Source/WebKit/UIProcess/API/gtk/WebKitBrowserInspector.h
@@ -0,0 +1,81 @@
+/*
+ * 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*,
+                                                      const char* defaultProxyURI,
+                                                      const char* const* ignoreHosts);
+
+G_END_DECLS
+
+#endif
diff --git a/Source/WebKit/UIProcess/API/gtk/webkit2.h b/Source/WebKit/UIProcess/API/gtk/webkit2.h
index c358118360a38c7b462227aa4ab8388bd7942c3e..70bdfbda231b481e8c5ac34fe6d8825f2350d71e 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/PageClientImpl.cpp b/Source/WebKit/UIProcess/API/wpe/PageClientImpl.cpp
index c8b41f407774d2337e99cc7f9151ec65be3fc532..22faf21f9a7946a7898cedfc1b6ec1316110a166 100644
--- a/Source/WebKit/UIProcess/API/wpe/PageClientImpl.cpp
+++ b/Source/WebKit/UIProcess/API/wpe/PageClientImpl.cpp
@@ -194,7 +194,7 @@ WebCore::IntPoint PageClientImpl::accessibilityScreenToRootView(const WebCore::I
 
 WebCore::IntRect PageClientImpl::rootViewToAccessibilityScreen(const WebCore::IntRect& rect)
 {
-    return rootViewToScreen(rect);    
+    return rootViewToScreen(rect);
 }
 
 void PageClientImpl::doneWithKeyEvent(const NativeWebKeyboardEvent&, bool)
diff --git a/Source/WebKit/UIProcess/API/wpe/WebKitBrowserInspector.h b/Source/WebKit/UIProcess/API/wpe/WebKitBrowserInspector.h
new file mode 100644
index 0000000000000000000000000000000000000000..0e8b78b60e8f306c98295afb5c7e5ed150e4918e
--- /dev/null
+++ b/Source/WebKit/UIProcess/API/wpe/WebKitBrowserInspector.h
@@ -0,0 +1,81 @@
+/*
+ * 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*,
+                                                      const char* defaultProxyURI,
+                                                      const char* const* ignoreHosts);
+
+G_END_DECLS
+
+#endif
diff --git a/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackend.cpp b/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackend.cpp
index e0fc205b39095cf8aae201a1dcca520461c60de4..872186ad99a7b82f0c61705ff6c5ae4453e5e1d4 100644
--- a/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackend.cpp
+++ b/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackend.cpp
@@ -54,6 +54,7 @@ struct _WebKitWebViewBackend {
     struct wpe_view_backend* backend;
     GDestroyNotify notifyCallback;
     gpointer notifyCallbackData;
+    take_screenshot_callback screenshotCallback;
     int referenceCount { 1 };
 };
 
@@ -116,6 +117,19 @@ struct wpe_view_backend* webkit_web_view_backend_get_wpe_backend(WebKitWebViewBa
     return viewBackend->backend;
 }
 
+void webkit_web_view_backend_set_screenshot_callback(WebKitWebViewBackend *view_backend, take_screenshot_callback callback)
+{
+    view_backend->screenshotCallback = callback;
+}
+
+cairo_surface_t* webkitWebViewBackendTakeScreenshot(WebKitWebViewBackend* view_backend)
+{
+    if (!view_backend->screenshotCallback)
+        return nullptr;
+
+    return view_backend->screenshotCallback(view_backend->notifyCallbackData);
+}
+
 namespace WTF {
 
 template <> WebKitWebViewBackend* refGPtr(WebKitWebViewBackend* ptr)
diff --git a/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackend.h b/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackend.h
index 6663964d5abac79e123d90e0351590884c66aa72..13ba5e7c3895c6e4efda95f1f90b9baea1c1bf30 100644
--- a/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackend.h
+++ b/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackend.h
@@ -27,6 +27,7 @@
 #include <glib-object.h>
 #include <wpe/WebKitDefines.h>
 #include <wpe/wpe.h>
+#include <cairo.h>
 
 G_BEGIN_DECLS
 
@@ -44,6 +45,12 @@ webkit_web_view_backend_new             (struct wpe_view_backend *backend,
 WEBKIT_API struct wpe_view_backend *
 webkit_web_view_backend_get_wpe_backend (WebKitWebViewBackend    *view_backend);
 
+typedef cairo_surface_t* (*take_screenshot_callback)(gpointer              user_data);
+
+WEBKIT_API void
+webkit_web_view_backend_set_screenshot_callback   (WebKitWebViewBackend      *view_backend,
+                                                   take_screenshot_callback  callback);
+
 G_END_DECLS
 
 #endif /* WebKitWebViewBackend_h */
diff --git a/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackendPrivate.h b/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackendPrivate.h
index e4b92ace1531090ae38a7aec3d3d4febf19aee84..43690f9ef4969a39084501613bfc00a77fd5df49 100644
--- a/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackendPrivate.h
+++ b/Source/WebKit/UIProcess/API/wpe/WebKitWebViewBackendPrivate.h
@@ -31,3 +31,5 @@ template <> void derefGPtr(WebKitWebViewBackend* ptr);
 }
 
 void webkitWebViewBackendUnref(WebKitWebViewBackend*);
+
+cairo_surface_t* webkitWebViewBackendTakeScreenshot(WebKitWebViewBackend*);
diff --git a/Source/WebKit/UIProcess/API/wpe/docs/wpe-1.0-sections.txt b/Source/WebKit/UIProcess/API/wpe/docs/wpe-1.0-sections.txt
index b9429bb65d00f9ee60a112b57f1a15b987cae31f..99d30744a7fad37dfa48f56cdd4f1eb0e5884b85 100644
--- a/Source/WebKit/UIProcess/API/wpe/docs/wpe-1.0-sections.txt
+++ b/Source/WebKit/UIProcess/API/wpe/docs/wpe-1.0-sections.txt
@@ -315,6 +315,8 @@ WEBKIT_TYPE_WEB_VIEW_BACKEND
 WebKitWebViewBackend
 webkit_web_view_backend_get_wpe_backend
 webkit_web_view_backend_new
+take_screenshot_callback
+webkit_web_view_backend_set_screenshot_callback
 
 <SUBSECTION Private>
 webkit_web_view_backend_get_type
diff --git a/Source/WebKit/UIProcess/API/wpe/webkit.h b/Source/WebKit/UIProcess/API/wpe/webkit.h
index 27c680d46428d349b0d1119f12da56ff283a60aa..1980aff7d662a1eea450d2db78b41f12a04f715e 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/Automation/WebAutomationSession.h b/Source/WebKit/UIProcess/Automation/WebAutomationSession.h
index 3627660395cb5f44e77a9f861d42e971dba1bbfc..4a1fb710da6b69be39c5b6bf54ee2b86689d7b5a 100644
--- a/Source/WebKit/UIProcess/Automation/WebAutomationSession.h
+++ b/Source/WebKit/UIProcess/Automation/WebAutomationSession.h
@@ -216,6 +216,8 @@ public:
     void markEventAsSynthesizedForAutomation(NSEvent *);
 #endif
 
+    static Optional<String> platformGetBase64EncodedPNGData(const ViewSnapshot&);
+
 private:
     WebPageProxy* webPageProxyForHandle(const String&);
     String handleForWebPageProxy(const WebPageProxy&);
@@ -264,7 +266,6 @@ private:
 
     // Get base64-encoded PNG data from a bitmap.
     static Optional<String> platformGetBase64EncodedPNGData(const ShareableBitmap::Handle&);
-    static Optional<String> platformGetBase64EncodedPNGData(const ViewSnapshot&);
 
     // Save base64-encoded file contents to a local file path and return the path.
     // This reuses the basename of the remote file path so that the filename exposed to DOM API remains the same.
diff --git a/Source/WebKit/UIProcess/BrowserInspectorPipe.cpp b/Source/WebKit/UIProcess/BrowserInspectorPipe.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..dc8af6fe1c57bcd62d605fd1daa3da13361858bb
--- /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 "InspectorPlaywrightAgent.h"
+#include "RemoteInspectorPipe.h"
+#include <wtf/NeverDestroyed.h>
+#include "InspectorPlaywrightAgentClient.h"
+
+namespace WebKit {
+
+void initializeBrowserInspectorPipe(std::unique_ptr<InspectorPlaywrightAgentClient> client)
+{
+    class BrowserInspectorPipe {
+    public:
+        BrowserInspectorPipe(std::unique_ptr<InspectorPlaywrightAgentClient> client)
+            : m_playwrightAgent(std::move(client))
+            , m_remoteInspectorPipe(m_playwrightAgent)
+        {
+        }
+
+        InspectorPlaywrightAgent m_playwrightAgent;
+        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..cd66887de171cda7d15a8e4dc6dbff63665dc619
--- /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 InspectorPlaywrightAgentClient;
+
+void initializeBrowserInspectorPipe(std::unique_ptr<InspectorPlaywrightAgentClient> client);
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/Cocoa/PageClientImplCocoa.mm b/Source/WebKit/UIProcess/Cocoa/PageClientImplCocoa.mm
index c7484a54558b8fbbecd74717c159a915a6114423..2c8809ef697cb9e54356fd9dbb41ea4425ef00e4 100644
--- a/Source/WebKit/UIProcess/Cocoa/PageClientImplCocoa.mm
+++ b/Source/WebKit/UIProcess/Cocoa/PageClientImplCocoa.mm
@@ -36,7 +36,7 @@ namespace WebKit {
 
 PageClientImplCocoa::PageClientImplCocoa(WKWebView *webView)
     : m_webView { webView }
-    , m_alternativeTextUIController { makeUnique<AlternativeTextUIController>() }
+    , m_alternativeTextUIController { makeUnique<WebCore::AlternativeTextUIController>() }
 {
 }
 
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 cdefd4287b1f5b2222d50ac6dab195dab236fc34..b8ee75742ce3569aaf668395d8dfe0bc6cafb6f7 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*, FrameInfoData&&, Function<void()>&& completionHandler) final;
         void runJavaScriptConfirm(WebPageProxy&, const WTF::String&, WebFrameProxy*, FrameInfoData&&, Function<void(bool)>&& completionHandler) final;
         void runJavaScriptPrompt(WebPageProxy&, const WTF::String&, const WTF::String&, WebFrameProxy*, FrameInfoData&&, 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&, const FrameInfoData&, 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 49c7142785ec29b446fd956978195a197d39b93f..537a3300b9b2b97001f3811cd85630683316b361 100644
--- a/Source/WebKit/UIProcess/Cocoa/UIDelegate.mm
+++ b/Source/WebKit/UIProcess/Cocoa/UIDelegate.mm
@@ -99,6 +99,7 @@ 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:)];
@@ -338,6 +339,15 @@ void UIDelegate::UIClient::runJavaScriptPrompt(WebPageProxy& page, const WTF::St
     }).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 021bacb7b940462fbf5820baa55395a9ed5bb142..f6b6bfbfdd12d6b6eaf6a04b5ee0dba4321ef878 100644
--- a/Source/WebKit/UIProcess/Cocoa/WebProcessPoolCocoa.mm
+++ b/Source/WebKit/UIProcess/Cocoa/WebProcessPoolCocoa.mm
@@ -385,7 +385,7 @@ void WebProcessPool::platformInitializeWebProcess(const WebProcessProxy& process
     auto screenProperties = WebCore::collectScreenProperties();
     parameters.screenProperties = WTFMove(screenProperties);
 #if PLATFORM(MAC)
-    parameters.useOverlayScrollbars = ([NSScroller preferredScrollerStyle] == NSScrollerStyleOverlay);
+    parameters.useOverlayScrollbars = m_configuration->forceOverlayScrollbars() || ([NSScroller preferredScrollerStyle] == NSScrollerStyleOverlay);
 #endif
     
 #if PLATFORM(IOS)
@@ -676,8 +676,8 @@ 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/Cocoa/WebViewImpl.h b/Source/WebKit/UIProcess/Cocoa/WebViewImpl.h
index d8f25b7ed5194616f064f5e2e1c3ec81490608b3..54048e141a5c23186191718f91fad219d66dbfe6 100644
--- a/Source/WebKit/UIProcess/Cocoa/WebViewImpl.h
+++ b/Source/WebKit/UIProcess/Cocoa/WebViewImpl.h
@@ -478,6 +478,9 @@ public:
     void provideDataForPasteboard(NSPasteboard *, NSString *type);
     NSArray *namesOfPromisedFilesDroppedAtDestination(NSURL *dropDestination);
 
+// Paywright begin
+    RetainPtr<CGImageRef> takeSnapshotForAutomation();
+// Paywright end
     RefPtr<ViewSnapshot> takeViewSnapshot();
     void saveBackForwardSnapshotForCurrentItem();
     void saveBackForwardSnapshotForItem(WebBackForwardListItem&);
diff --git a/Source/WebKit/UIProcess/Cocoa/WebViewImpl.mm b/Source/WebKit/UIProcess/Cocoa/WebViewImpl.mm
index 1145bd4400770377a68759664ef3db9102048c15..9c16b517712ab3969f6b6063b62ad064d668bc95 100644
--- a/Source/WebKit/UIProcess/Cocoa/WebViewImpl.mm
+++ b/Source/WebKit/UIProcess/Cocoa/WebViewImpl.mm
@@ -4435,6 +4435,18 @@ static RetainPtr<CGImageRef> takeWindowSnapshot(CGSWindowID windowID, bool captu
     return adoptCF(CGWindowListCreateImage(CGRectNull, kCGWindowListOptionIncludingWindow, windowID, imageOptions));
 }
 
+// Paywright begin
+RetainPtr<CGImageRef> WebViewImpl::takeSnapshotForAutomation() {
+    NSWindow *window = [m_view window];
+
+    CGSWindowID windowID = (CGSWindowID)window.windowNumber;
+    if (!windowID || !window.isVisible)
+        return nullptr;
+
+    return takeWindowSnapshot(windowID, false);
+}
+// Paywright end
+
 RefPtr<ViewSnapshot> WebViewImpl::takeViewSnapshot()
 {
     NSWindow *window = [m_view window];
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..d7ed4f58f033ebfc13142f2d6e8814d6dd13dd8e 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/Function.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/Downloads/DownloadProxy.cpp b/Source/WebKit/UIProcess/Downloads/DownloadProxy.cpp
index c5de4e7d0f59194f43a023b089e372c58cf8ee06..c0f38eccf578c14d13cb3b42788f988b9917e7ac 100644
--- a/Source/WebKit/UIProcess/Downloads/DownloadProxy.cpp
+++ b/Source/WebKit/UIProcess/Downloads/DownloadProxy.cpp
@@ -42,8 +42,10 @@
 #include <WebCore/MIMETypeRegistry.h>
 #include <WebCore/ResourceResponseBase.h>
 #include <wtf/FileSystem.h>
+#include <wtf/NeverDestroyed.h>
 #include <wtf/text/CString.h>
 #include <wtf/text/WTFString.h>
+#include <wtf/UUID.h>
 
 namespace WebKit {
 using namespace WebCore;
@@ -62,7 +64,10 @@ DownloadProxy::DownloadProxy(DownloadProxyMap& downloadProxyMap, WebsiteDataStor
     , m_request(resourceRequest)
     , m_originatingPage(makeWeakPtr(originatingPage))
     , m_frameInfo(API::FrameInfo::create(FrameInfoData { frameInfoData }, originatingPage))
+    , m_uuid(createCanonicalUUIDString())
 {
+    if (auto* instrumentation = m_dataStore->downloadInstrumentation())
+      instrumentation->downloadCreated(*m_dataStore, m_uuid, m_request, frameInfoData, originatingPage);
 }
 
 DownloadProxy::~DownloadProxy()
@@ -178,7 +183,21 @@ void DownloadProxy::decideDestinationWithSuggestedFilenameAsync(DownloadID downl
 {
     if (!m_processPool)
         return;
-    
+
+    if (auto* instrumentation = m_dataStore->downloadInstrumentation())
+      instrumentation->downloadFilenameSuggested(*m_dataStore, m_uuid, suggestedFilename);
+
+    if (m_processPool->networkProcess() && m_dataStore->allowDownloadForAutomation()) {
+        SandboxExtension::Handle sandboxExtensionHandle;
+        String destination;
+        if (*m_dataStore->allowDownloadForAutomation()) {
+            destination = FileSystem::pathByAppendingComponent(m_dataStore->downloadPathForAutomation(), m_uuid);
+            SandboxExtension::createHandle(destination, SandboxExtension::Type::ReadWrite, sandboxExtensionHandle);
+        }
+        m_processPool->networkProcess()->send(Messages::NetworkProcess::ContinueDecidePendingDownloadDestination(downloadID, destination, sandboxExtensionHandle, true), 0);
+        return;
+    }
+
     m_processPool->downloadClient().decideDestinationWithSuggestedFilename(*this, ResourceResponseBase::sanitizeSuggestedFilename(suggestedFilename), [this, protectedThis = makeRef(*this), downloadID = downloadID] (AllowOverwrite allowOverwrite, String destination) {
         SandboxExtension::Handle sandboxExtensionHandle;
         if (!destination.isNull())
@@ -206,6 +225,8 @@ void DownloadProxy::didFinish()
         return;
 
     m_processPool->downloadClient().didFinish(*this);
+    if (auto* instrumentation = m_dataStore->downloadInstrumentation())
+      instrumentation->downloadFinished(*m_dataStore, m_uuid, String());
 
     // This can cause the DownloadProxy object to be deleted.
     m_downloadProxyMap.downloadFinished(*this);
@@ -227,6 +248,8 @@ void DownloadProxy::didFail(const ResourceError& error, const IPC::DataReference
     m_resumeData = createData(resumeData);
 
     m_processPool->downloadClient().didFail(*this, error);
+    if (auto* instrumentation = m_dataStore->downloadInstrumentation())
+      instrumentation->downloadFinished(*m_dataStore, m_uuid, error.localizedDescription());
 
     // This can cause the DownloadProxy object to be deleted.
     m_downloadProxyMap.downloadFinished(*this);
@@ -234,9 +257,14 @@ void DownloadProxy::didFail(const ResourceError& error, const IPC::DataReference
 
 void DownloadProxy::didCancel(const IPC::DataReference& resumeData)
 {
+    if (!m_processPool)
+        return;
+
     m_resumeData = createData(resumeData);
 
     m_processPool->downloadClient().didCancel(*this);
+    if (auto* instrumentation = m_dataStore->downloadInstrumentation())
+      instrumentation->downloadFinished(*m_dataStore, m_uuid, "canceled"_s);
 
     // This can cause the DownloadProxy object to be deleted.
     m_downloadProxyMap.downloadFinished(*this);
diff --git a/Source/WebKit/UIProcess/Downloads/DownloadProxy.h b/Source/WebKit/UIProcess/Downloads/DownloadProxy.h
index b19499a662b48e10e876b403c168dbde9bf9f3ec..2a0384a1936471f27727a6c06905704a4686ddc8 100644
--- a/Source/WebKit/UIProcess/Downloads/DownloadProxy.h
+++ b/Source/WebKit/UIProcess/Downloads/DownloadProxy.h
@@ -133,6 +133,7 @@ private:
     Vector<URL> m_redirectChain;
     bool m_wasUserInitiated { true };
     Ref<API::FrameInfo> m_frameInfo;
+    String m_uuid;
 };
 
 } // namespace WebKit
diff --git a/Source/WebKit/UIProcess/DrawingAreaProxy.h b/Source/WebKit/UIProcess/DrawingAreaProxy.h
index 59cdfdafab1d85ea3a5aecb3cd2293e6dfb1eb8d..52fe7990b1c18b964ee3cfa9f324e3c2875eefe9 100644
--- a/Source/WebKit/UIProcess/DrawingAreaProxy.h
+++ b/Source/WebKit/UIProcess/DrawingAreaProxy.h
@@ -75,6 +75,7 @@ public:
 
     const WebCore::IntSize& size() const { return m_size; }
     bool setSize(const WebCore::IntSize&, const WebCore::IntSize& scrollOffset = { });
+    void waitForSizeUpdate(Function<void ()>&&);
 
 #if USE(COORDINATED_GRAPHICS) || USE(TEXTURE_MAPPER)
     // The timeout we use when waiting for a DidUpdateGeometry message.
diff --git a/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.cpp b/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..d9f9c4b81174f9f0a8ae77cf5163a259ccd58fad
--- /dev/null
+++ b/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.cpp
@@ -0,0 +1,271 @@
+/*
+ * 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 "InspectorScreencastAgent.h"
+
+#include "PageClient.h"
+#include "WebAutomationSession.h"
+#include "WebPageProxy.h"
+#include <JavaScriptCore/InspectorFrontendDispatchers.h>
+#include <JavaScriptCore/InspectorFrontendRouter.h>
+#include <WebCore/NotImplemented.h>
+
+#if PLATFORM(GTK)
+#include "DrawingAreaProxy.h"
+#include "ScreencastEncoder.h"
+#include <WebCore/ImageBufferUtilitiesCairo.h>
+#include <gtk/gtk.h>
+#include <wtf/text/Base64.h>
+#endif
+#if PLATFORM(WPE)
+#include "DrawingAreaProxy.h"
+#include "ScreencastEncoder.h"
+#endif
+
+namespace WebKit {
+
+using namespace Inspector;
+
+InspectorScreencastAgent::InspectorScreencastAgent(BackendDispatcher& backendDispatcher, Inspector::FrontendRouter& frontendRouter, WebPageProxy& page)
+    : InspectorAgentBase("Screencast"_s)
+    , m_frontendDispatcher(makeUnique<ScreencastFrontendDispatcher>(frontendRouter))
+    , m_backendDispatcher(ScreencastBackendDispatcher::create(backendDispatcher, this))
+    , m_page(page)
+{
+}
+
+InspectorScreencastAgent::~InspectorScreencastAgent()
+{
+}
+
+void InspectorScreencastAgent::didCreateFrontendAndBackend(FrontendRouter*, BackendDispatcher*)
+{
+}
+
+void InspectorScreencastAgent::willDestroyFrontendAndBackend(DisconnectReason)
+{
+    ErrorString errorString;
+    stop(errorString);
+}
+
+#if USE(COORDINATED_GRAPHICS)
+void InspectorScreencastAgent::didPaint(cairo_surface_t* surface)
+{
+#if PLATFORM(GTK) || PLATFORM(WPE)
+    if (m_encoder)
+        m_encoder->encodeFrame(surface, m_page.drawingArea()->size());
+#else
+    UNUSED_PARAM(surface);
+#endif
+}
+#endif
+
+void InspectorScreencastAgent::start(Inspector::ErrorString& errorString, const String& format, const int* quality)
+{
+    if (m_enabled)
+        return;
+
+    if (format == "jpeg") {
+        m_format = ImageFormat::Jpeg;
+    } else if (format == "png") {
+        m_format = ImageFormat::Png;
+    } else {
+        errorString = "Unsupported format"_s;
+        return;
+    }
+
+    if (quality && (*quality < 0 || *quality >100)) {
+        errorString = "Unsupported quality"_s;
+        return;
+    }
+
+    m_enabled = true;
+    if (quality)
+        m_quality = *quality;
+    fprintf(stderr, "InspectorScreencastAgent::start %p\n", this);
+#if PLATFORM(GTK)
+    g_signal_connect_swapped(m_page.viewWidget(), "draw", reinterpret_cast<GCallback>(InspectorScreencastAgent::webViewDrawCallback), this);
+#else
+    scheduleSnapshot();
+#endif
+}
+
+void InspectorScreencastAgent::stop(Inspector::ErrorString&)
+{
+    if (!m_enabled)
+        return;
+
+    m_enabled = false;
+    m_inflightFrames = 0;
+    m_quality = WTF::nullopt;
+#if PLATFORM(GTK)
+    g_signal_handlers_disconnect_by_func(m_page.viewWidget(), reinterpret_cast<gpointer>(InspectorScreencastAgent::webViewDrawCallback), this);
+#endif
+}
+
+void InspectorScreencastAgent::frameAck(Inspector::ErrorString& errorString)
+{
+    fprintf(stderr, "InspectorScreencastAgent::frameAck m_inflightFrames=%d\n", m_inflightFrames);
+    if (!m_inflightFrames) {
+        errorString = "No inflight frames to ack"_s;
+        return;
+    }
+
+    --m_inflightFrames;
+#if !PLATFORM(GTK)
+    scheduleSnapshot();
+#endif
+}
+
+void InspectorScreencastAgent::startVideoRecording(Inspector::ErrorString& errorString, const String& file, int width, int height, const double* scale)
+{
+#if PLATFORM(GTK) || PLATFORM(WPE)
+    if (m_encoder) {
+        errorString = "Already recording"_s;
+        return;
+    }
+
+    if (width < 10 || width > 10000 || height < 10 || height > 10000) {
+        errorString = "Invalid size"_s;
+        return;
+    }
+    Optional<double> optionalScale;
+    if (scale) {
+        if (*scale <= 0 || *scale > 1) {
+            errorString = "Unsupported scale"_s;
+            return;
+        }
+
+        optionalScale = *scale;
+    }
+    m_encoder = ScreencastEncoder::create(errorString, file, IntSize(width, height), optionalScale);
+    if (!m_encoder)
+        return;
+
+#else
+    errorString = "Not implemented"_s;
+#endif
+}
+
+void InspectorScreencastAgent::stopVideoRecording(Ref<StopVideoRecordingCallback>&& callback)
+{
+#if PLATFORM(GTK) || PLATFORM(WPE)
+    if (!m_encoder) {
+        callback->sendFailure("Not recording"_s);
+        return;
+    }
+
+    m_encoder->finish([protectRef = m_encoder.copyRef(), callback = WTFMove(callback)] {
+        callback->sendSuccess();
+    });
+    m_encoder = nullptr;
+#else
+    callback->sendFailure("Not implemented"_s);
+#endif
+}
+
+void InspectorScreencastAgent::scheduleSnapshot()
+{
+    if (!m_enabled)
+        return;
+
+    fprintf(stderr, "InspectorScreencastAgent::scheduleSnapshot m_inflightFrames=%d\n", m_inflightFrames);
+
+    m_page.callAfterNextPresentationUpdate([agent = makeWeakPtr(this)](CallbackBase::Error error) mutable {
+        fprintf(stderr, "callAfterNextPresentationUpdate 1 error= %d\n", error);
+        if (!agent)
+            return;
+
+        fprintf(stderr, "callAfterNextPresentationUpdate 2 error= %d\n", error);
+        if (error == CallbackBase::Error::None) {
+            agent->takeSnapshot();
+        } else {
+            fprintf(stderr, "callAfterNextPresentationUpdate error= %d\n", error);
+        }
+        agent->scheduleSnapshot();
+        fprintf(stderr, "callAfterNextPresentationUpdate 3 error= %d\n", error);
+    });
+}
+
+void InspectorScreencastAgent::takeSnapshot()
+{
+    if (!m_enabled)
+        return;
+
+    if (m_inflightFrames > 2)
+        return;
+
+    String snapshot = platformTakeSnapshot();
+    ++m_inflightFrames;
+    m_frontendDispatcher->frame(snapshot);
+}
+
+#if PLATFORM(GTK)
+gboolean InspectorScreencastAgent::webViewDrawCallback(InspectorScreencastAgent* agent)
+{
+    agent->takeSnapshot();
+    // Let default handler draw on the screen.
+    return FALSE;
+}
+
+String InspectorScreencastAgent::platformTakeSnapshot()
+{
+    auto viewSnapshot = m_page.takeViewSnapshot(WTF::nullopt);
+    if (!viewSnapshot) {
+        fprintf(stderr, "   takeViewSnapshot failed\n");
+        return String();
+    }
+
+    String format;
+    switch (m_format) {
+    case ImageFormat::Jpeg:
+        format = "image/jpeg";
+        break;
+    case ImageFormat::Png:
+        format = "image/png";
+        break;
+    };
+
+    Optional<double> quality;
+    if (m_quality)
+        quality = *m_quality / 100.0;
+
+    Vector<uint8_t> data = WebCore::data(viewSnapshot->surface(), format, quality);
+    return base64Encode(data);
+}
+
+#elif PLATFORM(COCOA)
+// in its own file
+#else
+String InspectorScreencastAgent::platformTakeSnapshot()
+{
+    // WPE and Windows implementation lives in the Web Process.
+    notImplemented();
+    return String();
+}
+#endif
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.h b/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.h
new file mode 100644
index 0000000000000000000000000000000000000000..9b18c5ff9e18cd1c40df8ccd2daefeb7974e4d74
--- /dev/null
+++ b/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.h
@@ -0,0 +1,89 @@
+/*
+ * 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
+
+#include <JavaScriptCore/InspectorAgentBase.h>
+#include <JavaScriptCore/InspectorBackendDispatchers.h>
+
+#include <wtf/Forward.h>
+#include <wtf/Noncopyable.h>
+#include <wtf/WeakPtr.h>
+
+namespace Inspector {
+class BackendDispatcher;
+class FrontendChannel;
+class FrontendRouter;
+class ScreencastFrontendDispatcher;
+}
+
+namespace WebKit {
+
+class ScreencastEncoder;
+class WebPageProxy;
+
+class InspectorScreencastAgent : public Inspector::InspectorAgentBase, public Inspector::ScreencastBackendDispatcherHandler, public CanMakeWeakPtr<InspectorScreencastAgent> {
+    WTF_MAKE_NONCOPYABLE(InspectorScreencastAgent);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    InspectorScreencastAgent(Inspector::BackendDispatcher& backendDispatcher, Inspector::FrontendRouter& frontendRouter, WebPageProxy& page);
+    ~InspectorScreencastAgent() override;
+
+    void didCreateFrontendAndBackend(Inspector::FrontendRouter*, Inspector::BackendDispatcher*) override;
+    void willDestroyFrontendAndBackend(Inspector::DisconnectReason) override;
+
+#if USE(COORDINATED_GRAPHICS)
+    void didPaint(cairo_surface_t*);
+#endif
+
+    void start(Inspector::ErrorString&, const String& format, const int* quality) override;
+    void stop(Inspector::ErrorString&) override;
+    void frameAck(Inspector::ErrorString&) override;
+    void startVideoRecording(Inspector::ErrorString&, const String& file, int width, int height, const double* scale) override;
+    void stopVideoRecording(Ref<StopVideoRecordingCallback>&&) override;
+
+
+private:
+#if PLATFORM(GTK)
+    static gboolean webViewDrawCallback(InspectorScreencastAgent*);
+#endif
+    void scheduleSnapshot();
+    void takeSnapshot();
+    String platformTakeSnapshot();
+
+    std::unique_ptr<Inspector::ScreencastFrontendDispatcher> m_frontendDispatcher;
+    Ref<Inspector::ScreencastBackendDispatcher> m_backendDispatcher;
+    WebPageProxy& m_page;
+    bool m_enabled { false };
+    int m_inflightFrames { 0 };
+    enum class ImageFormat { Jpeg, Png };
+    ImageFormat m_format { ImageFormat::Jpeg };
+    Optional<int> m_quality;
+#if PLATFORM(GTK) || PLATFORM(WPE)
+    RefPtr<ScreencastEncoder> m_encoder;
+#endif
+};
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/Inspector/Agents/ScreencastEncoder.cpp b/Source/WebKit/UIProcess/Inspector/Agents/ScreencastEncoder.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..3fe6f5d5b0bf43f79e452addb8ac21bf3c3bf904
--- /dev/null
+++ b/Source/WebKit/UIProcess/Inspector/Agents/ScreencastEncoder.cpp
@@ -0,0 +1,410 @@
+/*
+ * Copyright (c) 2010, The WebM Project authors. All rights reserved.
+ * Copyright (c) 2013 The Chromium Authors. All rights reserved.
+ * 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 "ScreencastEncoder.h"
+
+#include <cairo.h>
+#include <libyuv.h>
+#include <vpx/vp8.h>
+#include <vpx/vp8cx.h>
+#include <vpx/vpx_encoder.h>
+#include <wtf/MonotonicTime.h>
+#include <wtf/RunLoop.h>
+#include <wtf/WorkQueue.h>
+
+using namespace WebCore;
+
+namespace WebKit {
+
+namespace {
+// Defines the dimension of a macro block. This is used to compute the active
+// map for the encoder.
+const int kMacroBlockSize = 16;
+
+void createImage(unsigned int width, unsigned int height,
+                 std::unique_ptr<vpx_image_t>& out_image,
+                 std::unique_ptr<uint8_t[]>& out_image_buffer) {
+  std::unique_ptr<vpx_image_t> image(new vpx_image_t());
+  memset(image.get(), 0, sizeof(vpx_image_t));
+
+  // libvpx seems to require both to be assigned.
+  image->d_w = width;
+  image->w = width;
+  image->d_h = height;
+  image->h = height;
+
+  // I420
+  image->fmt = VPX_IMG_FMT_YV12;
+  image->x_chroma_shift = 1;
+  image->y_chroma_shift = 1;
+
+  // libyuv's fast-path requires 16-byte aligned pointers and strides, so pad
+  // the Y, U and V planes' strides to multiples of 16 bytes.
+  const int y_stride = ((image->w - 1) & ~15) + 16;
+  const int uv_unaligned_stride = y_stride >> image->x_chroma_shift;
+  const int uv_stride = ((uv_unaligned_stride - 1) & ~15) + 16;
+
+  // libvpx accesses the source image in macro blocks, and will over-read
+  // if the image is not padded out to the next macroblock: crbug.com/119633.
+  // Pad the Y, U and V planes' height out to compensate.
+  // Assuming macroblocks are 16x16, aligning the planes' strides above also
+  // macroblock aligned them.
+  static_assert(kMacroBlockSize == 16, "macroblock_size_not_16");
+  const int y_rows = ((image->h - 1) & ~(kMacroBlockSize-1)) + kMacroBlockSize;
+  const int uv_rows = y_rows >> image->y_chroma_shift;
+
+  // Allocate a YUV buffer large enough for the aligned data & padding.
+  const int buffer_size = y_stride * y_rows + 2*uv_stride * uv_rows;
+  std::unique_ptr<uint8_t[]> image_buffer(new uint8_t[buffer_size]);
+
+  // Reset image value to 128 so we just need to fill in the y plane.
+  memset(image_buffer.get(), 128, buffer_size);
+
+  // Fill in the information for |image_|.
+  unsigned char* uchar_buffer =
+      reinterpret_cast<unsigned char*>(image_buffer.get());
+  image->planes[0] = uchar_buffer;
+  image->planes[1] = image->planes[0] + y_stride * y_rows;
+  image->planes[2] = image->planes[1] + uv_stride * uv_rows;
+  image->stride[0] = y_stride;
+  image->stride[1] = uv_stride;
+  image->stride[2] = uv_stride;
+
+  out_image = std::move(image);
+  out_image_buffer = std::move(image_buffer);
+}
+
+void mem_put_le16(void *vmem, int val) {
+  unsigned char *mem = (unsigned char *)vmem;
+
+  mem[0] = (unsigned char)((val >> 0) & 0xff);
+  mem[1] = (unsigned char)((val >> 8) & 0xff);
+}
+
+void mem_put_le32(void *vmem, int val) {
+  unsigned char *mem = (unsigned char *)vmem;
+
+  mem[0] = (unsigned char)((val >>  0) & 0xff);
+  mem[1] = (unsigned char)((val >>  8) & 0xff);
+  mem[2] = (unsigned char)((val >> 16) & 0xff);
+  mem[3] = (unsigned char)((val >> 24) & 0xff);
+}
+
+void ivf_write_file_header_with_video_info(FILE *outfile, uint32_t fourcc,
+                                           int frame_cnt, int frame_width,
+                                           int frame_height,
+                                           vpx_rational_t timebase) {
+  char header[32];
+
+  header[0] = 'D';
+  header[1] = 'K';
+  header[2] = 'I';
+  header[3] = 'F';
+  mem_put_le16(header + 4, 0);              // version
+  mem_put_le16(header + 6, 32);             // header size
+  mem_put_le32(header + 8, fourcc);         // fourcc
+  mem_put_le16(header + 12, frame_width);   // width
+  mem_put_le16(header + 14, frame_height);  // height
+  mem_put_le32(header + 16, timebase.den);  // rate
+  mem_put_le32(header + 20, timebase.num);  // scale
+  mem_put_le32(header + 24, frame_cnt);     // length
+  mem_put_le32(header + 28, 0);             // unused
+
+  fwrite(header, 1, 32, outfile);
+}
+
+void ivf_write_file_header(FILE *outfile, const struct vpx_codec_enc_cfg *cfg,
+                           uint32_t fourcc, int frame_cnt) {
+  ivf_write_file_header_with_video_info(outfile, fourcc, frame_cnt, cfg->g_w,
+                                        cfg->g_h, cfg->g_timebase);
+}
+
+void ivf_write_frame_header(FILE *outfile, int64_t pts, size_t frame_size) {
+  char header[12];
+
+  mem_put_le32(header, (int)frame_size);
+  mem_put_le32(header + 4, (int)(pts & 0xFFFFFFFF));
+  mem_put_le32(header + 8, (int)(pts >> 32));
+  fwrite(header, 1, 12, outfile);
+}
+
+} // namespace
+
+class ScreencastEncoder::VPXFrame {
+    WTF_MAKE_NONCOPYABLE(VPXFrame);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    explicit VPXFrame(RefPtr<cairo_surface_t>&& surface)
+        : m_surface(WTFMove(surface))
+    { }
+
+    void setDuration(int duration) { m_duration = duration; }
+    int duration() const { return m_duration; }
+
+    void convertToVpxImage(vpx_image_t* image)
+    {
+        // Convert the updated region to YUV ready for encoding.
+        const uint8_t* rgba_data = cairo_image_surface_get_data(m_surface.get());
+        int rgba_stride = cairo_image_surface_get_stride(m_surface.get());
+
+        const int y_stride = image->stride[0];
+        ASSERT(image->stride[1] == image->stride[2]);
+        const int uv_stride = image->stride[1];
+        uint8_t* y_data = image->planes[0];
+        uint8_t* u_data = image->planes[1];
+        uint8_t* v_data = image->planes[2];
+
+        // TODO: redraw only damaged regions?
+        libyuv::ARGBToI420(rgba_data, rgba_stride,
+                            y_data, y_stride,
+                            u_data, uv_stride,
+                            v_data, uv_stride,
+                            image->w, image->h);
+    }
+
+private:
+    RefPtr<cairo_surface_t> m_surface;
+    int m_duration = 0;
+};
+
+
+class ScreencastEncoder::VPXCodec {
+public:
+    VPXCodec(uint32_t fourcc, vpx_codec_ctx_t codec, vpx_codec_enc_cfg_t cfg, FILE* file)
+        : m_encoderQueue(WorkQueue::create("Screencast encoder"))
+        , m_fourcc(fourcc)
+        , m_codec(codec)
+        , m_cfg(cfg)
+        , m_file(file)
+    {
+        ivf_write_file_header(m_file, &m_cfg, m_fourcc, 0);
+
+        createImage(cfg.g_w, cfg.g_h, m_image, m_imageBuffer);
+    }
+
+    void encodeFrameAsync(std::unique_ptr<VPXFrame>&& frame)
+    {
+        m_encoderQueue->dispatch([this, frame = WTFMove(frame)] {
+            frame->convertToVpxImage(m_image.get());
+            // TODO: figure out why passing duration to the codec results in much
+            // worse visual quality and makes video stutter.
+            for (int i = 0; i < frame->duration(); i++)
+                encodeFrame(m_image.get(), 1);
+        });
+    }
+
+    void finishAsync(Function<void()>&& callback)
+    {
+        m_encoderQueue->dispatch([this, callback = WTFMove(callback)] {
+            finish();
+            callback();
+        });
+    }
+
+private:
+    bool encodeFrame(vpx_image_t *img, int duration)
+    {
+        vpx_codec_iter_t iter = nullptr;
+        const vpx_codec_cx_pkt_t *pkt = nullptr;
+        int flags = 0;
+        const vpx_codec_err_t res = vpx_codec_encode(&m_codec, img, m_pts, duration, flags, VPX_DL_REALTIME);
+        if (res != VPX_CODEC_OK) {
+            fprintf(stderr, "Failed to encode frame: %s\n", vpx_codec_error(&m_codec));
+            return false;
+        }
+
+        bool gotPkts = false;
+        while ((pkt = vpx_codec_get_cx_data(&m_codec, &iter)) != nullptr) {
+            gotPkts = true;
+
+            if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
+                ivf_write_frame_header(m_file, m_pts, pkt->data.frame.sz);
+                if (fwrite(pkt->data.frame.buf, 1, pkt->data.frame.sz, m_file) != pkt->data.frame.sz) {
+                    fprintf(stderr, "Failed to write compressed frame\n");
+                    return 0;
+                }
+                bool keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY) != 0;
+                ++m_frameCount;
+                fprintf(stderr, "  #%03d %spts=%ld sz=%ld\n", m_frameCount, keyframe ? "[K] " : "", pkt->data.frame.pts, pkt->data.frame.sz);
+                m_pts += pkt->data.frame.duration;
+            }
+        }
+
+        return gotPkts;
+    }
+
+    void finish()
+    {
+        // Flush encoder.
+        while (encodeFrame(nullptr, 1))
+            ++m_frameCount;
+
+        rewind(m_file);
+        // Update total frame count.
+        ivf_write_file_header(m_file, &m_cfg, m_fourcc, m_frameCount);
+        fclose(m_file);
+        fprintf(stderr, "ScreencastEncoder::finish %d frames\n", m_frameCount);
+    }
+
+    Ref<WorkQueue> m_encoderQueue;
+    uint32_t m_fourcc { 0 };
+    vpx_codec_ctx_t m_codec;
+    vpx_codec_enc_cfg_t m_cfg;
+    FILE* m_file { nullptr };
+    int m_frameCount { 0 };
+    int64_t m_pts { 0 };
+    std::unique_ptr<uint8_t[]> m_imageBuffer;
+    std::unique_ptr<vpx_image_t> m_image;
+};
+
+ScreencastEncoder::ScreencastEncoder(std::unique_ptr<VPXCodec>&& vpxCodec, IntSize size, Optional<double> scale)
+    : m_vpxCodec(WTFMove(vpxCodec))
+    , m_size(size)
+    , m_scale(scale)
+{
+    ASSERT(!size.isZero());
+}
+
+ScreencastEncoder::~ScreencastEncoder()
+{
+}
+
+static constexpr uint32_t vp8fourcc = 0x30385056;
+static constexpr uint32_t vp9fourcc = 0x30395056;
+static constexpr int fps = 30;
+
+RefPtr<ScreencastEncoder> ScreencastEncoder::create(String& errorString, const String& filePath, IntSize size, Optional<double> scale)
+{
+    const uint32_t fourcc = vp8fourcc;
+    vpx_codec_iface_t* codec_interface = vpx_codec_vp8_cx();
+    if (!codec_interface) {
+        errorString = "Codec not found.";
+        return nullptr;
+    }
+
+    if (size.width() <= 0 || size.height() <= 0 || (size.width() % 2) != 0 || (size.height() % 2) != 0) {
+        errorString = makeString("Invalid frame size: "_s, size.width(), "x"_s, size.height());
+        return nullptr;
+    }
+
+    vpx_codec_enc_cfg_t cfg;
+    memset(&cfg, 0, sizeof(cfg));
+    vpx_codec_err_t error = vpx_codec_enc_config_default(codec_interface, &cfg, 0);
+    if (error) {
+        errorString = makeString("Failed to get default codec config: "_s, vpx_codec_err_to_string(error));
+        return nullptr;
+    }
+
+    cfg.g_w = size.width();
+    cfg.g_h = size.height();
+    cfg.g_timebase.num = 1;
+    cfg.g_timebase.den = fps;
+    cfg.g_error_resilient = VPX_ERROR_RESILIENT_DEFAULT;
+
+    vpx_codec_ctx_t codec;
+    if (vpx_codec_enc_init(&codec, codec_interface, &cfg, 0)) {
+        errorString = makeString("Failed to initialize encoder: "_s, vpx_codec_error(&codec));
+        return nullptr;
+    }
+
+    FILE* file = fopen(filePath.utf8().data(), "wb");
+    if (!file) {
+        errorString = makeString("Failed to open file '", filePath, "' for writing: ", strerror(errno));
+        return nullptr;
+    }
+
+    std::unique_ptr<VPXCodec> vpxCodec(new VPXCodec(fourcc, codec, cfg, file));
+    fprintf(stderr, "ScreencastEncoder initialized with: %s\n", vpx_codec_iface_name(codec_interface));
+    return adoptRef(new ScreencastEncoder(WTFMove(vpxCodec), size, scale));
+}
+
+void ScreencastEncoder::flushLastFrame()
+{
+    MonotonicTime now = MonotonicTime::now();
+    if (m_lastFrameTimestamp) {
+        // If previous frame encoding failed for some rason leave the timestampt intact.
+        if (!m_lastFrame)
+            return;
+
+        Seconds seconds = now - m_lastFrameTimestamp;
+        int duration = 1 + seconds.seconds() * fps; // Duration in timebase units
+        m_lastFrame->setDuration(duration);
+        m_vpxCodec->encodeFrameAsync(WTFMove(m_lastFrame));
+    }
+    m_lastFrameTimestamp = now;
+}
+
+void ScreencastEncoder::encodeFrame(cairo_surface_t* drawingAreaSurface, IntSize size)
+{
+    fprintf(stderr, "ScreencastEncoder::encodeFrame\n");
+    flushLastFrame();
+    // Note that in WPE drawing area size is updated asynchronously and may differ from acutal
+    // size of the surface.
+    if (size.isZero()) {
+        fprintf(stderr, "Cairo surface size is 0\n");
+        return;
+    }
+
+    // TODO: adjust device scale factor?
+    RefPtr<cairo_surface_t> surface = adoptRef(cairo_image_surface_create(CAIRO_FORMAT_ARGB32, m_size.width(), m_size.height()));
+    {
+        RefPtr<cairo_t> cr = adoptRef(cairo_create(surface.get()));
+
+        // TODO: compare to libyuv scale functions?
+        cairo_matrix_t transform;
+        if (m_scale) {
+            cairo_matrix_init_scale(&transform, *m_scale, *m_scale);
+            cairo_transform(cr.get(), &transform);
+        }
+
+        // Record top left part of the drawing area that fits into the frame.
+        cairo_set_source_surface(cr.get(), drawingAreaSurface, 0, 0);
+        cairo_paint(cr.get());
+    }
+    cairo_surface_flush(surface.get());
+
+    m_lastFrame = makeUnique<VPXFrame>(WTFMove(surface));
+}
+
+void ScreencastEncoder::finish(Function<void()>&& callback)
+{
+    if (!m_vpxCodec) {
+        callback();
+        return;
+    }
+
+    flushLastFrame();
+    m_vpxCodec->finishAsync([callback = WTFMove(callback)] () mutable {
+        RunLoop::main().dispatch([callback = WTFMove(callback)] {
+            callback();
+        });
+    });
+}
+
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/Inspector/Agents/ScreencastEncoder.h b/Source/WebKit/UIProcess/Inspector/Agents/ScreencastEncoder.h
new file mode 100644
index 0000000000000000000000000000000000000000..0f1209d8e96391d050261dcef4225b30fecc90cd
--- /dev/null
+++ b/Source/WebKit/UIProcess/Inspector/Agents/ScreencastEncoder.h
@@ -0,0 +1,62 @@
+/*
+ * 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
+
+#include <WebCore/IntSize.h>
+#include <wtf/Forward.h>
+#include <wtf/Noncopyable.h>
+#include <wtf/ThreadSafeRefCounted.h>
+#include <wtf/WeakPtr.h>
+
+namespace WebKit {
+
+class WebPageProxy;
+
+class ScreencastEncoder : public ThreadSafeRefCounted<ScreencastEncoder> {
+    WTF_MAKE_NONCOPYABLE(ScreencastEncoder);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    static RefPtr<ScreencastEncoder> create(String& errorString, const String& filePath, WebCore::IntSize, Optional<double> scale);
+
+    class VPXCodec;
+    ScreencastEncoder(std::unique_ptr<VPXCodec>&&, WebCore::IntSize, Optional<double> scale);
+    ~ScreencastEncoder();
+
+    void encodeFrame(cairo_surface_t*, WebCore::IntSize);
+    void finish(Function<void()>&& callback);
+
+private:
+    void flushLastFrame();
+
+    std::unique_ptr<VPXCodec> m_vpxCodec;
+    const WebCore::IntSize m_size;
+    Optional<double> m_scale;
+    MonotonicTime m_lastFrameTimestamp;
+    class VPXFrame;
+    std::unique_ptr<VPXFrame> m_lastFrame;
+};
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/Inspector/InspectorTargetProxy.cpp b/Source/WebKit/UIProcess/Inspector/InspectorTargetProxy.cpp
index 6928ca2fbfb6939062e3cd14bb7ba6f2fdc87f5f..621b99e233ed5cf504fedbd3ca3209c03bcd611f 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)
 {
@@ -97,6 +95,31 @@ 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 1861cff806131196ea49b4f8aca6665beebbf6e8..2d910fb6867a257e7bd9f1741c192f1e51f02071 100644
--- a/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.cpp
+++ b/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.cpp
@@ -26,12 +26,20 @@
 #include "config.h"
 #include "WebPageInspectorController.h"
 
+#include "APINavigation.h"
 #include "InspectorBrowserAgent.h"
+#include "InspectorDialogAgent.h"
+#include "InspectorScreencastAgent.h"
 #include "ProvisionalPageProxy.h"
 #include "WebFrameProxy.h"
 #include "WebPageInspectorAgentBase.h"
+#include "WebPageInspectorEmulationAgent.h"
+#include "WebPageInspectorInputAgent.h"
 #include "WebPageInspectorTarget.h"
 #include "WebPageProxy.h"
+#include "WebPreferences.h"
+#include <WebCore/ResourceError.h>
+#include <WebCore/WindowFeatures.h>
 #include <JavaScriptCore/InspectorAgentBase.h>
 #include <JavaScriptCore/InspectorBackendDispatcher.h>
 #include <JavaScriptCore/InspectorBackendDispatchers.h>
@@ -48,27 +56,106 @@ 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_frontendRouter(FrontendRouter::create())
     , m_backendDispatcher(BackendDispatcher::create(m_frontendRouter.copyRef()))
     , m_page(page)
 {
-    auto targetAgent = makeUnique<InspectorTargetAgent>(m_frontendRouter.get(), m_backendDispatcher.get());
-    m_targetAgent = targetAgent.get();
-    m_agents.append(WTFMove(targetAgent));
 }
 
 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 !PLATFORM(WIN)
+    auto screencastAgent = makeUnique<InspectorScreencastAgent>(m_backendDispatcher.get(), m_frontendRouter.get(), m_page);
+    m_screecastAgent = screencastAgent.get();
+    m_agents.append(WTFMove(screencastAgent));
+#endif
+    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::didFinishAttachingToWebProcess()
+{
+    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::willCreateNewPage(const WebCore::WindowFeatures& features, const URL& url)
+{
+    if (s_observer)
+        s_observer->willCreateNewPage(m_page, features, url);
+}
+
+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
@@ -82,6 +169,17 @@ 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)
@@ -100,8 +198,10 @@ 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());
 
@@ -124,6 +224,8 @@ void WebPageInspectorController::disconnectAllFrontends()
     // Disconnect any remaining remote frontends.
     m_frontendRouter->disconnectAllFrontends();
 
+    m_pendingNavigations.clear();
+
     m_page.didChangeInspectorFrontendCount(m_frontendRouter->frontendCount());
 
 #if ENABLE(REMOTE_INSPECTOR)
@@ -150,6 +252,66 @@ void WebPageInspectorController::setIndicating(bool indicating)
 }
 #endif
 
+#if USE(COORDINATED_GRAPHICS)
+void WebPageInspectorController::didPaint(cairo_surface_t* surface)
+{
+    if (!m_frontendRouter->hasFrontends())
+        return;
+
+    m_screecastAgent->didPaint(surface);
+}
+#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));
@@ -169,6 +331,33 @@ 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())
@@ -188,7 +377,7 @@ 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)
@@ -241,4 +430,20 @@ 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 c2df3ceb4b69f32060dcbd90d04dc6cb5900de0d..429f37267632b18077e25d7547ad48cac5a55de9 100644
--- a/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.h
+++ b/Source/WebKit/UIProcess/Inspector/WebPageInspectorController.h
@@ -26,17 +26,27 @@
 #pragma once
 
 #include "InspectorTargetProxy.h"
+#include "ProcessTerminationReason.h"
 #include <JavaScriptCore/InspectorAgentRegistry.h>
 #include <JavaScriptCore/InspectorTargetAgent.h>
 #include <WebCore/PageIdentifier.h>
 #include <wtf/Forward.h>
 #include <wtf/Noncopyable.h>
 #include <wtf/text/WTFString.h>
+#include <wtf/URL.h>
 
 namespace Inspector {
 class BackendDispatcher;
 class FrontendChannel;
 class FrontendRouter;
+class InspectorTarget;
+}
+
+namespace WebCore {
+class ResourceError;
+class ResourceRequest;
+enum class PolicyAction : uint8_t;
+struct WindowFeatures;
 }
 
 namespace WebKit {
@@ -44,6 +54,22 @@ namespace WebKit {
 class InspectorBrowserAgent;
 struct WebPageAgentContext;
 
+class InspectorScreencastAgent;
+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;
+    virtual void willCreateNewPage(WebPageProxy&, const WebCore::WindowFeatures&, const URL&) = 0;
+
+protected:
+    virtual ~WebPageInspectorControllerObserver() = default;
+};
+
 class WebPageInspectorController {
     WTF_MAKE_NONCOPYABLE(WebPageInspectorController);
     WTF_MAKE_FAST_ALLOCATED;
@@ -51,7 +77,19 @@ public:
     WebPageInspectorController(WebPageProxy&);
 
     void init();
+    void didFinishAttachingToWebProcess();
+
+    static void setObserver(WebPageInspectorControllerObserver*);
+
     void pageClosed();
+    bool pageCrashed(ProcessTerminationReason);
+
+    void willCreateNewPage(const WebCore::WindowFeatures&, const URL&);
+
+    void didShowPage();
+
+    void didProcessAllPendingKeyboardEvents();
+    void didProcessAllPendingMouseEvents();
 
     bool hasLocalFrontend() const;
 
@@ -64,11 +102,25 @@ public:
 #if ENABLE(REMOTE_INSPECTOR)
     void setIndicating(bool);
 #endif
+#if USE(COORDINATED_GRAPHICS)
+    void didPaint(cairo_surface_t*);
+#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()>&&);
 
@@ -84,6 +136,7 @@ private:
     void createLazyAgents();
 
     void addTarget(std::unique_ptr<InspectorTargetProxy>&&);
+    void adjustPageSettings();
 
     Ref<Inspector::FrontendRouter> m_frontendRouter;
     Ref<Inspector::BackendDispatcher> m_backendDispatcher;
@@ -92,11 +145,17 @@ private:
     WebPageProxy& m_page;
 
     Inspector::InspectorTargetAgent* m_targetAgent;
+    WebPageInspectorEmulationAgent* m_emulationAgent { nullptr };
+    WebPageInspectorInputAgent* m_inputAgent { nullptr };
+    InspectorScreencastAgent* m_screecastAgent { nullptr };
     HashMap<String, std::unique_ptr<InspectorTargetProxy>> m_targets;
 
     InspectorBrowserAgent* m_enabledBrowserAgent;
 
     bool m_didCreateLazyAgents { false };
+    HashMap<uint64_t, NavigationHandler> m_pendingNavigations;
+
+    static WebPageInspectorControllerObserver* s_observer;
 };
 
 } // namespace WebKit
diff --git a/Source/WebKit/UIProcess/Inspector/mac/InspectorScreencastAgentMac.mm b/Source/WebKit/UIProcess/Inspector/mac/InspectorScreencastAgentMac.mm
new file mode 100644
index 0000000000000000000000000000000000000000..880273f9fc4410b5678ed391670f91ac51d86e37
--- /dev/null
+++ b/Source/WebKit/UIProcess/Inspector/mac/InspectorScreencastAgentMac.mm
@@ -0,0 +1,72 @@
+/*
+ * 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 "InspectorScreencastAgent.h"
+
+#if PLATFORM(MAC)
+
+#include "PageClient.h"
+#include <CoreGraphics/CoreGraphics.h>
+#include <WebCore/ImageBufferUtilitiesCG.h>
+#include <wtf/RetainPtr.h>
+#include <wtf/text/WTFString.h>
+
+namespace WebKit {
+
+using namespace Inspector;
+
+String InspectorScreencastAgent::platformTakeSnapshot()
+{
+    RetainPtr<CGImageRef> windowSnapshotImage = m_page.pageClient().takeSnapshotForAutomation();
+    if (!windowSnapshotImage)
+        return String();
+
+    CFStringRef type;
+    switch (m_format) {
+    case ImageFormat::Jpeg:
+        type = kUTTypeJPEG;
+        break;
+    case ImageFormat::Png:
+        type = kUTTypePNG;
+        break;
+    };
+
+    Optional<double> quality;
+    if (m_quality)
+        quality = *m_quality / 100.0;
+
+    RetainPtr<NSMutableData> imageData = adoptNS([[NSMutableData alloc] init]);
+    if (!WebCore::encodeImage(windowSnapshotImage.get(), type, quality, (CFMutableDataRef)imageData.get())) {
+        fprintf(stderr, "Failed to encode image.\n");
+        return String();
+    }
+
+    return String([imageData base64EncodedStringWithOptions:0]);
+}
+
+} // namespace WebKit
+
+#endif // PLATFORM(MAC)
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/InspectorPlaywrightAgent.cpp b/Source/WebKit/UIProcess/InspectorPlaywrightAgent.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..cea80a8f37fe56b3dc6eb3b36744c70c43a74282
--- /dev/null
+++ b/Source/WebKit/UIProcess/InspectorPlaywrightAgent.cpp
@@ -0,0 +1,819 @@
+/*
+ * 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 "InspectorPlaywrightAgent.h"
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "APIPageConfiguration.h"
+#include "FrameInfoData.h"
+#include "InspectorPlaywrightAgentClient.h"
+#include "InspectorTargetProxy.h"
+#include "NetworkProcessMessages.h"
+#include "NetworkProcessProxy.h"
+#include "PageClient.h"
+#include "WebAutomationSession.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/InspectorPageAgent.h>
+#include <WebCore/ProcessIdentifier.h>
+#include <WebCore/ResourceRequest.h>
+#include <WebCore/WindowFeatures.h>
+#include <JavaScriptCore/InspectorBackendDispatcher.h>
+#include <JavaScriptCore/InspectorFrontendChannel.h>
+#include <JavaScriptCore/InspectorFrontendRouter.h>
+#include <pal/SessionID.h>
+#include <stdlib.h>
+#include <wtf/HashMap.h>
+#include <wtf/HexNumber.h>
+#include <wtf/URL.h>
+
+
+using namespace Inspector;
+
+namespace WebKit {
+
+class InspectorPlaywrightAgent::PageProxyChannel : public FrontendChannel {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    PageProxyChannel(FrontendChannel& frontendChannel, String browserContextID, String pageProxyID, WebPageProxy& page)
+        : m_browserContextID(browserContextID)
+        , 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("browserContextId"_s, m_browserContextID);
+        messageObject->setString("pageProxyId"_s, m_pageProxyID);
+        return messageObject->toJSONString();
+    }
+
+    String m_browserContextID;
+    String m_pageProxyID;
+    FrontendChannel& m_frontendChannel;
+    WebPageProxy& m_page;
+};
+
+namespace {
+
+String toBrowserContextIDProtocolString(const PAL::SessionID& sessionID)
+{
+    StringBuilder builder;
+    builder.append(hex(sessionID.toUInt64(), 16));
+    return builder.toString();
+}
+
+String toPageProxyIDProtocolString(const WebPageProxy& page)
+{
+    return makeString(page.identifier().toUInt64());
+}
+
+
+static RefPtr<JSON::ArrayOf<String>> getEnabledWindowFeatures(const WebCore::WindowFeatures& features) {
+  auto result = JSON::ArrayOf<String>::create();
+  if (features.x)
+    result->addItem("left=" + String::number(*features.x));
+  if (features.y)
+    result->addItem("top=" + String::number(*features.y));
+  if (features.width)
+    result->addItem("width=" + String::number(*features.width));
+  if (features.height)
+    result->addItem("height=" + String::number(*features.height));
+  if (features.menuBarVisible)
+    result->addItem("menubar");
+  if (features.toolBarVisible)
+    result->addItem("toolbar");
+  if (features.statusBarVisible)
+    result->addItem("status");
+  if (features.locationBarVisible)
+    result->addItem("location");
+  if (features.scrollbarsVisible)
+    result->addItem("scrollbars");
+  if (features.resizable)
+    result->addItem("resizable");
+  if (features.fullscreen)
+    result->addItem("fullscreen");
+  if (features.dialog)
+    result->addItem("dialog");
+  if (features.noopener)
+    result->addItem("noopener");
+  if (features.noreferrer)
+    result->addItem("noreferrer");
+  for (const auto& additionalFeature : features.additionalFeatures)
+    result->addItem(additionalFeature);
+  return result;
+}
+
+Inspector::Protocol::Playwright::CookieSameSitePolicy cookieSameSitePolicy(WebCore::Cookie::SameSitePolicy policy)
+{
+    switch (policy) {
+    case WebCore::Cookie::SameSitePolicy::None:
+        return Inspector::Protocol::Playwright::CookieSameSitePolicy::None;
+    case WebCore::Cookie::SameSitePolicy::Lax:
+        return Inspector::Protocol::Playwright::CookieSameSitePolicy::Lax;
+    case WebCore::Cookie::SameSitePolicy::Strict:
+        return Inspector::Protocol::Playwright::CookieSameSitePolicy::Strict;
+    }
+    ASSERT_NOT_REACHED();
+    return Inspector::Protocol::Playwright::CookieSameSitePolicy::None;
+}
+
+Ref<Inspector::Protocol::Playwright::Cookie> buildObjectForCookie(const WebCore::Cookie& cookie)
+{
+    return Inspector::Protocol::Playwright::Cookie::create()
+        .setName(cookie.name)
+        .setValue(cookie.value)
+        .setDomain(cookie.domain)
+        .setPath(cookie.path)
+        .setExpires(cookie.expires.valueOr(-1))
+        .setHttpOnly(cookie.httpOnly)
+        .setSecure(cookie.secure)
+        .setSession(cookie.session)
+        .setSameSite(cookieSameSitePolicy(cookie.sameSite))
+        .release();
+}
+
+}  // 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 InspectorPlaywrightAgent::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;
+};
+
+
+InspectorPlaywrightAgent::InspectorPlaywrightAgent(std::unique_ptr<InspectorPlaywrightAgentClient> client)
+    : m_frontendChannel(nullptr)
+    , m_frontendRouter(FrontendRouter::create())
+    , m_backendDispatcher(BackendDispatcher::create(m_frontendRouter.copyRef()))
+    , m_client(std::move(client))
+    , m_frontendDispatcher(makeUnique<PlaywrightFrontendDispatcher>(m_frontendRouter))
+    , m_playwrightDispatcher(PlaywrightBackendDispatcher::create(m_backendDispatcher.get(), this))
+{
+}
+
+InspectorPlaywrightAgent::~InspectorPlaywrightAgent()
+{
+    if (m_frontendChannel)
+        disconnectFrontend();
+}
+
+void InspectorPlaywrightAgent::connectFrontend(FrontendChannel& frontendChannel)
+{
+    ASSERT(!m_frontendChannel);
+    m_frontendChannel = &frontendChannel;
+    WebPageInspectorController::setObserver(this);
+
+    m_frontendRouter->connectFrontend(frontendChannel);
+}
+
+void InspectorPlaywrightAgent::disconnectFrontend()
+{
+    ASSERT(m_frontendChannel);
+
+    ErrorString error;
+    disable(error);
+
+    m_frontendRouter->disconnectFrontend(*m_frontendChannel);
+    ASSERT(!m_frontendRouter->hasFrontends());
+
+    WebPageInspectorController::setObserver(nullptr);
+    m_frontendChannel = nullptr;
+}
+
+void InspectorPlaywrightAgent::dispatchMessageFromFrontend(const String& message)
+{
+    m_backendDispatcher->dispatch(message, [&](const RefPtr<JSON::Object>& messageObject) {
+        RefPtr<JSON::Value> idValue;
+        if (!messageObject->getValue("id"_s, idValue))
+            return BackendDispatcher::InterceptionResult::Continue;
+        RefPtr<JSON::Value> pageProxyIDValue;
+        if (!messageObject->getValue("pageProxyId"_s, pageProxyIDValue))
+            return BackendDispatcher::InterceptionResult::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::InterceptionResult::Intercepted;
+        }
+
+        if (auto pageProxyChannel = m_pageProxyChannels.get(pageProxyID)) {
+            pageProxyChannel->dispatchMessageFromFrontend(message);
+            return BackendDispatcher::InterceptionResult::Intercepted;
+        }
+
+        long requestId = 0;
+        if (!idValue->asInteger(requestId)) {
+            m_backendDispatcher->reportProtocolError(BackendDispatcher::InvalidRequest, "The type of 'id' must be number"_s);
+            m_backendDispatcher->sendPendingErrors();
+            return BackendDispatcher::InterceptionResult::Intercepted;
+        }
+
+        m_backendDispatcher->reportProtocolError(requestId, BackendDispatcher::InvalidParams, "Cannot find page proxy with provided 'pageProxyId'"_s);
+        m_backendDispatcher->sendPendingErrors();
+        return BackendDispatcher::InterceptionResult::Intercepted;
+    });
+}
+
+void InspectorPlaywrightAgent::didCreateInspectorController(WebPageProxy& page)
+{
+    if (!m_isEnabled)
+        return;
+
+    ASSERT(m_frontendChannel);
+
+    String browserContextID = toBrowserContextIDProtocolString(page.sessionID());
+    String pageProxyID = toPageProxyIDProtocolString(page);
+    auto* opener = page.configuration().relatedPage();
+    String openerId;
+    if (opener)
+        openerId = toPageProxyIDProtocolString(*opener);
+
+    m_frontendDispatcher->pageProxyCreated(
+        browserContextID, pageProxyID, openerId.isNull() ? nullptr : &openerId);
+
+    // Auto-connect to all new pages.
+    auto pageProxyChannel = makeUnique<PageProxyChannel>(*m_frontendChannel, browserContextID, pageProxyID, page);
+    page.inspectorController().connectFrontend(*pageProxyChannel);
+    // Always pause new targets if controlled remotely.
+    page.inspectorController().setPauseOnStart(true);
+    m_pageProxyChannels.set(pageProxyID, WTFMove(pageProxyChannel));
+}
+
+void InspectorPlaywrightAgent::willDestroyInspectorController(WebPageProxy& page)
+{
+    if (!m_isEnabled)
+        return;
+
+    m_frontendDispatcher->pageProxyDestroyed(
+        toBrowserContextIDProtocolString(page.sessionID()),
+        toPageProxyIDProtocolString(page));
+
+    auto it = m_browserContextDeletions.find(page.sessionID());
+    if (it != m_browserContextDeletions.end()) {
+        it->value->willDestroyPage(page);
+        if (it->value->isFinished())
+            m_browserContextDeletions.remove(it);
+    }
+
+    String pageProxyID = toPageProxyIDProtocolString(page);
+    auto channelIt = m_pageProxyChannels.find(pageProxyID);
+    ASSERT(channelIt != m_pageProxyChannels.end());
+    channelIt->value->disconnect();
+    m_pageProxyChannels.remove(channelIt);
+}
+
+void InspectorPlaywrightAgent::didFailProvisionalLoad(WebPageProxy& page, uint64_t navigationID, const String& error)
+{
+    if (!m_isEnabled)
+        return;
+
+    m_frontendDispatcher->provisionalLoadFailed(
+        toBrowserContextIDProtocolString(page.sessionID()),
+        toPageProxyIDProtocolString(page),
+        String::number(navigationID), error);
+}
+
+void InspectorPlaywrightAgent::willCreateNewPage(WebPageProxy& page, const WebCore::WindowFeatures& features, const URL& url)
+{
+    if (!m_isEnabled)
+        return;
+
+    m_frontendDispatcher->windowOpen(
+        toBrowserContextIDProtocolString(page.sessionID()),
+        toPageProxyIDProtocolString(page),
+        url.string(),
+        getEnabledWindowFeatures(features));
+}
+
+void InspectorPlaywrightAgent::enable(ErrorString&)
+{
+    if (m_isEnabled)
+        return;
+
+    m_isEnabled = true;
+    for (auto& pool : WebProcessPool::allProcessPools()) {
+        auto* dataStore = pool->websiteDataStore();
+        if (dataStore)
+            dataStore->setDownloadInstrumentation(this);
+        for (auto& process : pool->processes()) {
+            for (auto* page : process->pages())
+                didCreateInspectorController(*page);
+        }
+    }
+}
+
+void InspectorPlaywrightAgent::disable(ErrorString&)
+{
+    if (!m_isEnabled)
+        return;
+
+    m_isEnabled = false;
+
+    for (auto it = m_pageProxyChannels.begin(); it != m_pageProxyChannels.end(); ++it)
+        it->value->disconnect();
+    m_pageProxyChannels.clear();
+
+    for (auto& pool : WebProcessPool::allProcessPools()) {
+        auto* dataStore = pool->websiteDataStore();
+        if (dataStore) {
+            dataStore->setDownloadInstrumentation(nullptr);
+            dataStore->setDownloadForAutomation(Optional<bool>(), String());
+        }
+    }
+    for (auto& it : m_browserContexts)
+        it.value.dataStore->setDownloadInstrumentation(nullptr);
+    m_browserContextDeletions.clear();
+}
+
+void InspectorPlaywrightAgent::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 InspectorPlaywrightAgent::createContext(ErrorString& errorString, const String* proxyServer, const String* proxyBypassList, String* browserContextID)
+{
+    BrowserContext browserContext = m_client->createBrowserContext(errorString, proxyServer ? *proxyServer : String(), proxyBypassList ? *proxyBypassList : String());
+    if (!errorString.isEmpty())
+        return;
+    browserContext.processPool->setPrimaryDataStore(*browserContext.dataStore);
+    browserContext.processPool->ensureNetworkProcess(browserContext.dataStore.get());
+    browserContext.dataStore->setDownloadInstrumentation(this);
+
+    PAL::SessionID sessionID = browserContext.dataStore->sessionID();
+    *browserContextID = toBrowserContextIDProtocolString(sessionID);
+    m_browserContexts.set(*browserContextID, browserContext);
+}
+
+void InspectorPlaywrightAgent::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 InspectorPlaywrightAgent::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;
+    *pageProxyID = toPageProxyIDProtocolString(*page);
+}
+
+WebFrameProxy* InspectorPlaywrightAgent::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 InspectorPlaywrightAgent::navigate(const String& url, const String& pageProxyID, const String* frameID, const String* referrer, Ref<NavigateCallback>&& callback)
+{
+    auto* pageProxyChannel = m_pageProxyChannels.get(pageProxyID);
+    if (!pageProxyChannel) {
+        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() != &pageProxyChannel->page()) {
+            callback->sendFailure("Frame with specified is not from the specified page"_s);
+            return;
+        }
+    }
+
+    pageProxyChannel->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 InspectorPlaywrightAgent::setIgnoreCertificateErrors(ErrorString& errorString, const String* browserContextID, bool ignore)
+{
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty())
+        return;
+
+    PAL::SessionID sessionID = browserContext.dataStore->sessionID();
+    NetworkProcessProxy* networkProcess = browserContext.processPool->networkProcess();
+    networkProcess->send(Messages::NetworkProcess::SetIgnoreCertificateErrors(sessionID, ignore), 0);
+}
+
+void InspectorPlaywrightAgent::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::Playwright::Cookie>::create();
+            for (const auto& cookie : allCookies)
+                cookies->addItem(buildObjectForCookie(cookie));
+            callback->sendSuccess(WTFMove(cookies));
+        }, 0);
+}
+
+void InspectorPlaywrightAgent::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;
+        }
+
+        double expires;
+        if (obj->getDouble("expires", expires) && expires != -1)
+            cookie.expires = 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 InspectorPlaywrightAgent::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 InspectorPlaywrightAgent::setLanguages(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.dataStore->setLanguagesForAutomation(WTFMove(items));
+}
+
+void InspectorPlaywrightAgent::setDownloadBehavior(ErrorString& errorString, const String* behavior, const String* downloadPath, const String* browserContextID)
+{
+    BrowserContext browserContext = lookupBrowserContext(errorString, browserContextID);
+    if (!errorString.isEmpty())
+        return;
+    Optional<bool> allow;
+    if (behavior && *behavior == "allow"_s)
+      allow = true;
+    if (behavior && *behavior == "deny"_s)
+      allow = false;
+    browserContext.dataStore->setDownloadForAutomation(allow, downloadPath ? *downloadPath : String());
+}
+
+void InspectorPlaywrightAgent::setGeolocationOverride(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."_s;
+        return;
+    }
+    if (geolocation) {
+        double timestamp = 0;
+        double latitude = 0;
+        double longitude = 0;
+        double accuracy = 0;
+        if (!geolocation->getDouble("timestamp"_s, timestamp) ||
+            !geolocation->getDouble("latitude"_s, latitude) ||
+            !geolocation->getDouble("longitude"_s, longitude) ||
+            !geolocation->getDouble("accuracy"_s, 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);
+    }
+}
+
+void InspectorPlaywrightAgent::downloadCreated(const WebsiteDataStore& dataStore, const String& uuid, const WebCore::ResourceRequest& request, const FrameInfoData& frameInfoData, WebPageProxy* page)
+{
+    if (!m_isEnabled)
+        return;
+    String frameID = WebCore::InspectorPageAgent::makeFrameID(page->process().coreProcessIdentifier(), frameInfoData.frameID ? *frameInfoData.frameID : page->mainFrame()->frameID());
+    m_frontendDispatcher->downloadCreated(
+        toBrowserContextIDProtocolString(dataStore.sessionID()),
+        toPageProxyIDProtocolString(*page),
+        frameID,
+        uuid, request.url().string());
+}
+
+void InspectorPlaywrightAgent::downloadFilenameSuggested(const WebsiteDataStore& dataStore, const String& uuid, const String& suggestedFilename)
+{
+    if (!m_isEnabled)
+        return;
+    m_frontendDispatcher->downloadFilenameSuggested(
+        toBrowserContextIDProtocolString(dataStore.sessionID()),
+        uuid, suggestedFilename);
+}
+
+void InspectorPlaywrightAgent::downloadFinished(const WebsiteDataStore& dataStore, const String& uuid, const String& error)
+{
+    if (!m_isEnabled)
+        return;
+    m_frontendDispatcher->downloadFinished(
+        toBrowserContextIDProtocolString(dataStore.sessionID()),
+        uuid, error);
+}
+
+BrowserContext InspectorPlaywrightAgent::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/InspectorPlaywrightAgent.h b/Source/WebKit/UIProcess/InspectorPlaywrightAgent.h
new file mode 100644
index 0000000000000000000000000000000000000000..7b1b0c063c792ce7dddf338242d1914539cae76d
--- /dev/null
+++ b/Source/WebKit/UIProcess/InspectorPlaywrightAgent.h
@@ -0,0 +1,119 @@
+/*
+ * 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 "InspectorPlaywrightAgentClient.h"
+#include <JavaScriptCore/InspectorBackendDispatchers.h>
+#include "WebPageInspectorController.h"
+#include "WebProcessPool.h"
+#include <wtf/HashMap.h>
+#include <wtf/Forward.h>
+#include <wtf/Noncopyable.h>
+
+namespace Inspector {
+class BackendDispatcher;
+class FrontendChannel;
+class FrontendRouter;
+class PlaywrightFrontendDispatcher;
+}
+
+namespace PAL {
+class SessionID;
+}
+
+namespace WebKit {
+
+class WebFrameProxy;
+
+class InspectorPlaywrightAgent final
+    : public WebPageInspectorControllerObserver
+    , public Inspector::PlaywrightBackendDispatcherHandler
+    , public DownloadInstrumentation {
+    WTF_MAKE_NONCOPYABLE(InspectorPlaywrightAgent);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    explicit InspectorPlaywrightAgent(std::unique_ptr<InspectorPlaywrightAgentClient> client);
+    ~InspectorPlaywrightAgent() override;
+
+    // Transport
+    void connectFrontend(Inspector::FrontendChannel&);
+    void disconnectFrontend();
+    void dispatchMessageFromFrontend(const String& message);
+
+private:
+    class BrowserContextDeletion;
+    class PageProxyChannel;
+    class TargetHandler;
+
+    // WebPageInspectorControllerObserver
+    void didCreateInspectorController(WebPageProxy&) override;
+    void willDestroyInspectorController(WebPageProxy&) override;
+    void didFailProvisionalLoad(WebPageProxy&, uint64_t navigationID, const String& error) override;
+    void willCreateNewPage(WebPageProxy&, const WebCore::WindowFeatures&, const URL&) override;
+
+    // PlaywrightDispatcherHandler
+    void enable(Inspector::ErrorString&) override;
+    void disable(Inspector::ErrorString&) override;
+    void close(Ref<CloseCallback>&&) override;
+    void createContext(Inspector::ErrorString&, const String* proxyServer, const String* proxyBypassList, 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 setGeolocationOverride(Inspector::ErrorString&, const String* browserContextID, const JSON::Object* geolocation) override;
+    void setLanguages(Inspector::ErrorString&, const JSON::Array& languages, const String* browserContextID) override;
+    void setDownloadBehavior(Inspector::ErrorString&, const String* behavior, const String* downloadPath, const String* browserContextID) override;
+
+    // DownloadInstrumentation
+    void downloadCreated(const WebsiteDataStore&, const String& uuid, const WebCore::ResourceRequest&, const FrameInfoData& frameInfoData, WebPageProxy* page) override;
+    void downloadFilenameSuggested(const WebsiteDataStore&, const String& uuid, const String& suggestedFilename) override;
+    void downloadFinished(const WebsiteDataStore&, const String& uuid, const String& error) override;
+
+    BrowserContext lookupBrowserContext(Inspector::ErrorString&, const String* browserContextID);
+    WebFrameProxy* frameForID(const String& frameID, String& error);
+
+    Inspector::FrontendChannel* m_frontendChannel { nullptr };
+    Ref<Inspector::FrontendRouter> m_frontendRouter;
+    Ref<Inspector::BackendDispatcher> m_backendDispatcher;
+    std::unique_ptr<InspectorPlaywrightAgentClient> m_client;
+    std::unique_ptr<Inspector::PlaywrightFrontendDispatcher> m_frontendDispatcher;
+    Ref<Inspector::PlaywrightBackendDispatcher> m_playwrightDispatcher;
+    HashMap<String, std::unique_ptr<PageProxyChannel>> m_pageProxyChannels;
+    HashMap<String, BrowserContext> m_browserContexts;
+    HashMap<PAL::SessionID, std::unique_ptr<BrowserContextDeletion>> m_browserContextDeletions;
+    bool m_isEnabled { false };
+};
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/InspectorPlaywrightAgentClient.h b/Source/WebKit/UIProcess/InspectorPlaywrightAgentClient.h
new file mode 100644
index 0000000000000000000000000000000000000000..b254875dc7404aed56680db05bac65b6d5f9c50a
--- /dev/null
+++ b/Source/WebKit/UIProcess/InspectorPlaywrightAgentClient.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 InspectorPlaywrightAgentClient {
+public:
+    virtual ~InspectorPlaywrightAgentClient() = default;
+    virtual RefPtr<WebKit::WebPageProxy> createPage(WTF::String& error, const BrowserContext& context) = 0;
+    virtual void closeBrowser() = 0;
+    virtual BrowserContext createBrowserContext(WTF::String& error, const WTF::String& proxyServer, const WTF::String& proxyBypassList) = 0;
+    virtual void deleteBrowserContext(WTF::String& error, PAL::SessionID) = 0;
+};
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/Launcher/win/ProcessLauncherWin.cpp b/Source/WebKit/UIProcess/Launcher/win/ProcessLauncherWin.cpp
index 7a14cfba15c103a2d4fe263fa49d25af3c396ec2..3ee0e154349661632799057c71f1d1f1551c2d69 100644
--- a/Source/WebKit/UIProcess/Launcher/win/ProcessLauncherWin.cpp
+++ b/Source/WebKit/UIProcess/Launcher/win/ProcessLauncherWin.cpp
@@ -96,8 +96,11 @@ 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/PageClient.h b/Source/WebKit/UIProcess/PageClient.h
index 2e66628ab5c708fff1210e587cd4a8529b80e816..059df8d50dc61d44d62081aa264823bfb6232ee8 100644
--- a/Source/WebKit/UIProcess/PageClient.h
+++ b/Source/WebKit/UIProcess/PageClient.h
@@ -247,7 +247,7 @@ public:
     virtual void showSafeBrowsingWarning(const SafeBrowsingWarning&, CompletionHandler<void(Variant<ContinueUnsafeLoad, URL>&&)>&& completionHandler) { completionHandler(ContinueUnsafeLoad::Yes); }
     virtual void clearSafeBrowsingWarning() { }
     virtual void clearSafeBrowsingWarningIfForMainFrameNavigation() { }
-    
+
 #if ENABLE(DRAG_SUPPORT)
 #if PLATFORM(GTK)
     virtual void startDrag(WebCore::SelectionData&&, OptionSet<WebCore::DragOperation>, RefPtr<ShareableBitmap>&& dragImage) = 0;
@@ -286,6 +286,11 @@ public:
     virtual void selectionDidChange() = 0;
 #endif
 
+// Paywright begin
+#if PLATFORM(COCOA)
+    virtual RetainPtr<CGImageRef> takeSnapshotForAutomation() = 0;
+#endif
+// Paywright end
 #if PLATFORM(COCOA) || PLATFORM(GTK)
     virtual RefPtr<ViewSnapshot> takeViewSnapshot(Optional<WebCore::IntRect>&&) = 0;
 #endif
@@ -346,7 +351,7 @@ public:
     virtual void setTextIndicator(Ref<WebCore::TextIndicator>, WebCore::TextIndicatorWindowLifetime) = 0;
     virtual void clearTextIndicator(WebCore::TextIndicatorWindowDismissalAnimation) = 0;
     virtual void setTextIndicatorAnimationProgress(float) = 0;
-    
+
     virtual void didPerformDictionaryLookup(const WebCore::DictionaryPopupInfo&) = 0;
 #endif
 
@@ -476,7 +481,7 @@ public:
     virtual bool hasSafeBrowsingWarning() const { return false; }
 
     virtual void setMouseEventPolicy(WebCore::MouseEventPolicy) { }
-    
+
 #if PLATFORM(MAC)
     virtual void didPerformImmediateActionHitTest(const WebHitTestResultData&, bool contentPreventsDefault, API::Object*) = 0;
     virtual NSObject *immediateActionAnimationControllerForHitTestResult(RefPtr<API::HitTestResult>, uint64_t, RefPtr<API::Object>) = 0;
diff --git a/Source/WebKit/UIProcess/RemoteInspectorPipe.cpp b/Source/WebKit/UIProcess/RemoteInspectorPipe.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..adcc4b59f90670f162bb2a798582723532e37ee0
--- /dev/null
+++ b/Source/WebKit/UIProcess/RemoteInspectorPipe.cpp
@@ -0,0 +1,221 @@
+/*
+ * 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 "InspectorPlaywrightAgent.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(InspectorPlaywrightAgent& playwrightAgent)
+    : m_playwrightAgent(playwrightAgent)
+{
+    // Initialize main loop before creating WorkQueue
+    WTF::RunLoop::initializeMain();
+    m_remoteFrontendChannel = makeUnique<RemoteFrontendChannel>();
+    start();
+}
+
+RemoteInspectorPipe::~RemoteInspectorPipe()
+{
+    stop();
+}
+
+bool RemoteInspectorPipe::start()
+{
+    if (m_receiverThread)
+        return true;
+
+#if PLATFORM(WIN)
+    readHandle = reinterpret_cast<HANDLE>(_get_osfhandle(readFD));
+    writeHandle = reinterpret_cast<HANDLE>(_get_osfhandle(writeFD));
+#endif
+
+    m_playwrightAgent.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_playwrightAgent.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_playwrightAgent.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..6d04f9290135069359ce6bf8726546482fd1dc95
--- /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 InspectorPlaywrightAgent;
+
+class RemoteInspectorPipe {
+    WTF_MAKE_NONCOPYABLE(RemoteInspectorPipe);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    explicit RemoteInspectorPipe(InspectorPlaywrightAgent&);
+    ~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;
+    InspectorPlaywrightAgent& m_playwrightAgent;
+};
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/WebAuthentication/Mock/MockLocalConnection.h b/Source/WebKit/UIProcess/WebAuthentication/Mock/MockLocalConnection.h
index ff90d3de4349c9a3385c20c059729b8e22ebe2e5..d5c4f2cd715551ddef6f5af93ada65cbe78ad213 100644
--- a/Source/WebKit/UIProcess/WebAuthentication/Mock/MockLocalConnection.h
+++ b/Source/WebKit/UIProcess/WebAuthentication/Mock/MockLocalConnection.h
@@ -28,6 +28,7 @@
 #if ENABLE(WEB_AUTHN)
 
 #include "LocalConnection.h"
+#include <WebCore/AuthenticatorAssertionResponse.h>
 #include <WebCore/MockWebAuthenticationConfiguration.h>
 
 namespace WebKit {
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..3983c25682b06bbbf9ae9fde95b5b9c349ae6abe
--- /dev/null
+++ b/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.cpp
@@ -0,0 +1,145 @@
+/*
+ * 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::grantPermissions(Inspector::ErrorString& errorString, const String& origin, const JSON::Array& values)
+{
+    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);
+    }
+    m_permissions.set(origin, WTFMove(set));
+    m_page.setPermissionsForAutomation(m_permissions);
+}
+
+void WebPageInspectorEmulationAgent::resetPermissions(Inspector::ErrorString&)
+{
+    m_permissions.clear();
+    m_page.setPermissionsForAutomation(m_permissions);
+}
+
+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..5ae0ce152f06b8316dbfbbbb2efd1990a31687d0
--- /dev/null
+++ b/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.h
@@ -0,0 +1,75 @@
+/*
+ * 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 grantPermissions(Inspector::ErrorString&, const String& origin, const JSON::Array& permissions) override;
+    void resetPermissions(Inspector::ErrorString&) 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;
+    HashMap<String, HashSet<String>> m_permissions;
+};
+
+} // namespace WebKit
diff --git a/Source/WebKit/UIProcess/WebPageInspectorInputAgent.cpp b/Source/WebKit/UIProcess/WebPageInspectorInputAgent.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5d19607e019489b33318be50ccdc94c2fcfae914
--- /dev/null
+++ b/Source/WebKit/UIProcess/WebPageInspectorInputAgent.cpp
@@ -0,0 +1,282 @@
+/*
+ * 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>
+#include <wtf/HexNumber.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;
+}
+
+static String keyIdentifierForKey(const String& key)
+{
+    if (key.length() == 1)
+        return makeString("U+", hex(toASCIIUpper(key.characterAt(0)), 4));
+    if (key == "Delete")
+        return "U+007F";
+    if (key == "Backspace")
+        return "U+0008";
+    if (key == "ArrowUp")
+        return "Up";
+    if (key == "ArrowDown")
+        return "Down";
+    if (key == "ArrowLeft")
+        return "Left";
+    if (key == "ArrowRight")
+        return "Right";
+    if (key == "Tab")
+        return "U+0009";
+    if (key == "Pause")
+        return "Pause";
+    if (key == "ScrollLock")
+        return "Scroll";
+    return key;
+}
+
+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);
+      }
+    }
+
+    String keyIdentifier = keyIdentifierForKey(eventKey);
+
+    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,
+        keyIdentifier,
+        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..20311d530090b0229010957a96fc60f44b4823fe
--- /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, const String& keyIdentifier, 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 4037ceef8668619ae52f1aa1a4b2783818d9c091..df126d71a13b80595fccfa586b23b78c6a6feeeb 100644
--- a/Source/WebKit/UIProcess/WebPageProxy.cpp
+++ b/Source/WebKit/UIProcess/WebPageProxy.cpp
@@ -953,6 +953,7 @@ void WebPageProxy::finishAttachingToWebProcess(ProcessLaunchReason reason)
     m_pageLoadState.didSwapWebProcesses();
     if (reason != ProcessLaunchReason::InitialProcess)
         m_drawingArea->waitForBackingStoreUpdateOnNextPaint();
+    m_inspectorController->didFinishAttachingToWebProcess();
 }
 
 void WebPageProxy::didAttachToRunningProcess()
@@ -1274,6 +1275,21 @@ 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)
@@ -1739,6 +1755,31 @@ 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());
@@ -1881,6 +1922,25 @@ 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())
@@ -2845,7 +2905,7 @@ 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();
@@ -2878,7 +2938,7 @@ 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
@@ -3307,6 +3367,7 @@ void WebPageProxy::receivedNavigationPolicyDecision(PolicyAction policyAction, A
 
 void WebPageProxy::receivedPolicyDecision(PolicyAction action, API::Navigation* navigation, RefPtr<API::WebsitePolicies>&& websitePolicies, Ref<PolicyDecisionSender>&& sender, Optional<SandboxExtension::Handle> sandboxExtensionHandle, 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;
@@ -4009,6 +4070,11 @@ void WebPageProxy::pageScaleFactorDidChange(double scaleFactor)
     m_pageScaleFactor = scaleFactor;
 }
 
+void WebPageProxy::viewScaleFactorDidChange(double scaleFactor)
+{
+    m_viewScaleFactor = scaleFactor;
+}
+
 void WebPageProxy::pluginScaleFactorDidChange(double pluginScaleFactor)
 {
     m_pluginScaleFactor = pluginScaleFactor;
@@ -4427,6 +4493,7 @@ void WebPageProxy::didDestroyNavigation(uint64_t navigationID)
 
     // FIXME: Message check the navigationID.
     m_navigationState->didDestroyNavigation(navigationID);
+    m_inspectorController->didDestroyNavigation(navigationID);
 }
 
 void WebPageProxy::didStartProvisionalLoadForFrame(FrameIdentifier frameID, FrameInfoData&& frameInfo, ResourceRequest&& request, uint64_t navigationID, URL&& url, URL&& unreachableURL, const UserData& userData)
@@ -4649,6 +4716,8 @@ 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;
@@ -5090,7 +5159,14 @@ void WebPageProxy::decidePolicyForNavigationActionAsync(FrameIdentifier frameID,
     NavigationActionData&& navigationActionData, FrameInfoData&& originatingFrameInfo, 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(frameInfo), identifier, navigationID, WTFMove(navigationActionData), WTFMove(originatingFrameInfo), originatingPageID, originalRequest, WTFMove(request), WTFMove(requestBody), WTFMove(redirectResponse), userData, listenerID);
+    if (m_inspectorController->shouldPauseLoading()) {
+        m_inspectorController->setContinueLoadingCallback([this, protectedThis = makeRef(*this), frameID, frameInfo = WTFMove(frameInfo), identifier, navigationID, navigationActionData = WTFMove(navigationActionData),
+                originatingFrameInfo = WTFMove(originatingFrameInfo), originatingPageID, originalRequest, request = WTFMove(request), requestBody = WTFMove(requestBody), redirectResponse = WTFMove(redirectResponse), userData, listenerID] () mutable {
+            decidePolicyForNavigationActionAsyncShared(m_process.copyRef(), m_webPageID, frameID, WTFMove(frameInfo), identifier, navigationID, WTFMove(navigationActionData), WTFMove(originatingFrameInfo), originatingPageID, originalRequest, WTFMove(request), WTFMove(requestBody), WTFMove(redirectResponse), userData, listenerID);
+        });
+    } else {
+        decidePolicyForNavigationActionAsyncShared(m_process.copyRef(), m_webPageID, frameID, WTFMove(frameInfo), identifier, navigationID, WTFMove(navigationActionData), WTFMove(originatingFrameInfo), originatingPageID, originalRequest, WTFMove(request), WTFMove(requestBody), WTFMove(redirectResponse), userData, listenerID);
+    }
 }
 
 void WebPageProxy::decidePolicyForNavigationActionAsyncShared(Ref<WebProcessProxy>&& process, PageIdentifier webPageID, FrameIdentifier frameID, FrameInfoData&& frameInfo,
@@ -5595,6 +5671,7 @@ void WebPageProxy::createNewPage(FrameInfoData&& originatingFrameInfoData, Optio
     auto* originatingPage = m_process->webPage(*originatingPageID);
     auto originatingFrameInfo = API::FrameInfo::create(WTFMove(originatingFrameInfoData), originatingPage);
     auto mainFrameURL = m_mainFrame ? m_mainFrame->url() : URL();
+    m_inspectorController->willCreateNewPage(windowFeatures, request.url());
     auto completionHandler = [this, protectedThis = makeRef(*this), mainFrameURL, request, reply = WTFMove(reply)] (RefPtr<WebPageProxy> newPage) mutable {
         if (!newPage) {
             reply(WTF::nullopt, WTF::nullopt);
@@ -5624,6 +5701,7 @@ void WebPageProxy::createNewPage(FrameInfoData&& originatingFrameInfoData, Optio
 void WebPageProxy::showPage()
 {
     m_uiClient->showPage(this);
+    m_inspectorController->didShowPage();
 }
 
 void WebPageProxy::exitFullscreenImmediately()
@@ -5678,6 +5756,8 @@ void WebPageProxy::runJavaScriptAlert(FrameIdentifier frameID, FrameInfoData&& f
         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(frameInfo), WTFMove(reply));
 }
 
@@ -5695,6 +5775,8 @@ void WebPageProxy::runJavaScriptConfirm(FrameIdentifier frameID, FrameInfoData&&
         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(frameInfo), WTFMove(reply));
 }
@@ -5713,6 +5795,8 @@ void WebPageProxy::runJavaScriptPrompt(FrameIdentifier frameID, FrameInfoData&&
         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(frameInfo), WTFMove(reply));
 }
@@ -5868,6 +5952,8 @@ void WebPageProxy::runBeforeUnloadConfirmPanel(FrameIdentifier frameID, FrameInf
             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();
@@ -6925,6 +7011,7 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
             if (auto* automationSession = process().processPool().automationSession())
                 automationSession->mouseEventsFlushedForPage(*this);
             didFinishProcessingAllPendingMouseEvents();
+            m_inspectorController->didProcessAllPendingMouseEvents();
         }
 
         break;
@@ -6951,7 +7038,6 @@ 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();
 
@@ -6971,7 +7057,6 @@ 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);
@@ -6980,6 +7065,7 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
         if (!canProcessMoreKeyEvents) {
             if (auto* automationSession = process().processPool().automationSession())
                 automationSession->keyboardEventsFlushedForPage(*this);
+            m_inspectorController->didProcessAllPendingKeyboardEvents();
         }
         break;
     }
@@ -7425,8 +7511,10 @@ static bool shouldReloadAfterProcessTermination(ProcessTerminationReason reason)
 void WebPageProxy::dispatchProcessDidTerminate(ProcessTerminationReason reason)
 {
     RELEASE_LOG_ERROR_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
@@ -7693,6 +7781,7 @@ void WebPageProxy::resetStateAfterProcessExited(ProcessTerminationReason termina
 
 WebPageCreationParameters WebPageProxy::creationParameters(WebProcessProxy& process, DrawingAreaProxy& drawingArea, RefPtr<API::WebsitePolicies>&& websitePolicies)
 {
+
     WebPageCreationParameters parameters;
 
     parameters.processDisplayName = configuration().processDisplayName();
@@ -7845,6 +7934,8 @@ WebPageCreationParameters WebPageProxy::creationParameters(WebProcessProxy& proc
     parameters.limitsNavigationsToAppBoundDomains = m_limitsNavigationsToAppBoundDomains;
     parameters.shouldRelaxThirdPartyCookieBlocking = m_configuration->shouldRelaxThirdPartyCookieBlocking();
 
+    parameters.shouldPauseInInspectorWhenShown = m_inspectorController->shouldPauseLoading();
+
 #if PLATFORM(GTK)
     parameters.themeName = pageClient().themeName();
 #endif
@@ -7916,6 +8007,14 @@ 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)
@@ -8001,7 +8100,8 @@ void WebPageProxy::requestGeolocationPermissionForFrame(GeolocationIdentifier ge
     MESSAGE_CHECK(m_process, frame);
 
     // FIXME: Geolocation should probably be using toString() as its string representation instead of databaseIdentifier().
-    auto origin = API::SecurityOrigin::create(frameInfo.securityOrigin.securityOrigin());
+    auto securityOrigin = frameInfo.securityOrigin.securityOrigin();
+    auto origin = API::SecurityOrigin::create(securityOrigin);
     auto request = m_geolocationPermissionRequestManager.createRequest(geolocationID);
     Function<void(bool)> completionHandler = [request = WTFMove(request)](bool allowed) {
         if (allowed)
@@ -8010,6 +8110,14 @@ void WebPageProxy::requestGeolocationPermissionForFrame(GeolocationIdentifier ge
             request->deny();
     };
 
+    auto permissions = m_permissionsForAutomation.find(securityOrigin->toString());
+    if (permissions == m_permissionsForAutomation.end())
+      permissions = m_permissionsForAutomation.find("*");
+    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
     // if there is no delegate instead of returning the completionHandler
diff --git a/Source/WebKit/UIProcess/WebPageProxy.h b/Source/WebKit/UIProcess/WebPageProxy.h
index 2edf44f59d498a8201a8ac7898493b5213e25da1..0f1644b556b26c5c2ffe7cc8c0e2a8938c9433d9 100644
--- a/Source/WebKit/UIProcess/WebPageProxy.h
+++ b/Source/WebKit/UIProcess/WebPageProxy.h
@@ -37,6 +37,7 @@
 #include "GeolocationIdentifier.h"
 #include "GeolocationPermissionRequestManagerProxy.h"
 #include "HiddenPageThrottlingAutoIncreasesCounter.h"
+#include "InspectorDialogAgent.h"
 #include "LayerTreeContext.h"
 #include "MessageSender.h"
 #include "NotificationPermissionRequestManagerProxy.h"
@@ -505,6 +506,8 @@ 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();
@@ -579,6 +582,11 @@ 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>&&);
 
@@ -604,6 +612,7 @@ 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);
@@ -1093,6 +1102,7 @@ public:
 #endif
 
     void pageScaleFactorDidChange(double);
+    void viewScaleFactorDidChange(double);
     void pluginScaleFactorDidChange(double);
     void pluginZoomFactorDidChange(double);
 
@@ -1413,6 +1423,8 @@ public:
 
 #if PLATFORM(COCOA) || PLATFORM(GTK)
     RefPtr<ViewSnapshot> takeViewSnapshot(Optional<WebCore::IntRect>&&);
+#elif PLATFORM(WPE)
+    RefPtr<ViewSnapshot> takeViewSnapshot(Optional<WebCore::IntRect>&&) { return nullptr; }
 #endif
 
 #if ENABLE(WEB_CRYPTO)
@@ -2395,6 +2407,7 @@ private:
     String m_overrideContentSecurityPolicy;
 
     RefPtr<WebInspectorProxy> m_inspector;
+    InspectorDialogAgent* m_inspectorDialogAgent { nullptr };
 
 #if ENABLE(FULLSCREEN_API)
     std::unique_ptr<WebFullScreenManagerProxy> m_fullScreenManager;
@@ -2823,6 +2836,9 @@ 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 83508e89e45608f2a4ff1119bc91e2e2550d4059..2633b9958022d179ee34c846480e9689bb042e88 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 WebKit::FrameInfoData frameInfo, String message) -> (bool result) Synchronous
     RunJavaScriptPrompt(WebCore::FrameIdentifier frameID, struct WebKit::FrameInfoData frameInfo, 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)
@@ -204,6 +205,7 @@ 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 358b420c9fa612aec82aa93a25940a4bbe96e275..97fcdf79397c05909584f297854912f9183f4379 100644
--- a/Source/WebKit/UIProcess/WebProcessPool.cpp
+++ b/Source/WebKit/UIProcess/WebProcessPool.cpp
@@ -1029,7 +1029,10 @@ void WebProcessPool::initializeNewWebProcess(WebProcessProxy& process, WebsiteDa
 #endif
 
     parameters.cacheModel = LegacyGlobalSettings::singleton().cacheModel();
-    parameters.languages = configuration().overrideLanguages().isEmpty() ? userPreferredLanguages() : configuration().overrideLanguages();
+    if (websiteDataStore && websiteDataStore->languagesForAutomation().size())
+        parameters.languages = websiteDataStore->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 5c60a32f978017fc5ae2d84e31273cea15a4d24c..a856ada5dd9ee83b136a0745c90bdf426dc88370 100644
--- a/Source/WebKit/UIProcess/WebProcessPool.h
+++ b/Source/WebKit/UIProcess/WebProcessPool.h
@@ -717,8 +717,8 @@ private:
 
     HashMap<uint64_t, RefPtr<DictionaryCallback>> m_dictionaryCallbacks;
 
-#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/WebsiteData/WebsiteDataStore.cpp b/Source/WebKit/UIProcess/WebsiteData/WebsiteDataStore.cpp
index 52c9f9402c3aebc366eb9c3da820ba30d772b4f7..1d6541cb7190699277ff4fc59ba29337a7a0968d 100644
--- a/Source/WebKit/UIProcess/WebsiteData/WebsiteDataStore.cpp
+++ b/Source/WebKit/UIProcess/WebsiteData/WebsiteDataStore.cpp
@@ -185,6 +185,8 @@ void WebsiteDataStore::registerProcess(WebProcessProxy& process)
 {
     ASSERT(process.pageCount() || process.provisionalPageCount());
     m_processes.add(process);
+    if (m_languagesForAutomation.size())
+        process.send(Messages::WebProcess::UserPreferredLanguagesChanged(m_languagesForAutomation), 0);
 }
 
 void WebsiteDataStore::unregisterProcess(WebProcessProxy& process)
@@ -2453,6 +2455,19 @@ void WebsiteDataStore::renameOriginInWebsiteData(URL&& oldName, URL&& newName, O
     }
 }
 
+void WebsiteDataStore::setLanguagesForAutomation(Vector<String>&& languages)
+{
+    m_languagesForAutomation = WTFMove(languages);
+    for (auto& process : processes())
+        process.send(Messages::WebProcess::UserPreferredLanguagesChanged(languages), 0);
+}
+
+void WebsiteDataStore::setDownloadForAutomation(Optional<bool> allow, const String& downloadPath)
+{
+    m_allowDownloadForAutomation = allow;
+    m_downloadPathForAutomation = downloadPath;
+}
+
 #if PLATFORM(COCOA)
 void WebsiteDataStore::forwardAppBoundDomainsToITPIfInitialized(CompletionHandler<void()>&& completionHandler)
 {
diff --git a/Source/WebKit/UIProcess/WebsiteData/WebsiteDataStore.h b/Source/WebKit/UIProcess/WebsiteData/WebsiteDataStore.h
index 964c6315e38f5e0a0303febce45b1e975054f0b4..6b6c4f18b617d0a87d05a17db739808929dff2a6 100644
--- a/Source/WebKit/UIProcess/WebsiteData/WebsiteDataStore.h
+++ b/Source/WebKit/UIProcess/WebsiteData/WebsiteDataStore.h
@@ -83,6 +83,7 @@ class WebResourceLoadStatisticsStore;
 enum class CacheModel : uint8_t;
 enum class WebsiteDataFetchOption;
 enum class WebsiteDataType;
+struct FrameInfoData;
 struct WebsiteDataRecord;
 struct WebsiteDataStoreParameters;
 
@@ -96,6 +97,16 @@ enum class StorageAccessPromptStatus;
 struct PluginModuleInfo;
 #endif
 
+class WebsiteDataStore;
+
+class DownloadInstrumentation {
+public:
+    virtual void downloadCreated(const WebsiteDataStore&, const String& uuid, const WebCore::ResourceRequest&, const FrameInfoData& frameInfoData, WebPageProxy* page) = 0;
+    virtual void downloadFilenameSuggested(const WebsiteDataStore&, const String& uuid, const String& suggestedFilename) = 0;
+    virtual void downloadFinished(const WebsiteDataStore&, const String& uuid, const String& error) = 0;
+    virtual ~DownloadInstrumentation() = default;
+};
+
 class WebsiteDataStore : public API::ObjectImpl<API::Object::Type::WebsiteDataStore>, public Identified<WebsiteDataStore>, public CanMakeWeakPtr<WebsiteDataStore>  {
 public:
     static Ref<WebsiteDataStore> defaultDataStore();
@@ -290,6 +301,14 @@ public:
     static WTF::String defaultJavaScriptConfigurationDirectory();
     static bool http3Enabled();
 
+    void setLanguagesForAutomation(Vector<String>&&);
+    Vector<String>& languagesForAutomation() { return m_languagesForAutomation; };
+    void setDownloadForAutomation(Optional<bool> allow, const String& downloadPath);
+    Optional<bool> allowDownloadForAutomation() { return m_allowDownloadForAutomation; };
+    String downloadPathForAutomation() { return m_downloadPathForAutomation; };
+    void setDownloadInstrumentation(DownloadInstrumentation* instrumentation) { m_downloadInstrumentation = instrumentation; };
+    DownloadInstrumentation* downloadInstrumentation() { return m_downloadInstrumentation; };
+
     void resetQuota(CompletionHandler<void()>&&);
     void hasAppBoundSession(CompletionHandler<void(bool)>&&) const;
     void clearAppBoundSession(CompletionHandler<void()>&&);
@@ -390,6 +409,11 @@ private:
 
     RefPtr<API::HTTPCookieStore> m_cookieStore;
 
+    Vector<String> m_languagesForAutomation;
+    Optional<bool> m_allowDownloadForAutomation;
+    String m_downloadPathForAutomation;
+    DownloadInstrumentation* m_downloadInstrumentation { nullptr };
+
 #if HAVE(APP_SSO)
     UniqueRef<SOAuthorizationCoordinator> m_soAuthorizationCoordinator;
 #endif
diff --git a/Source/WebKit/UIProcess/cairo/BackingStoreCairo.cpp b/Source/WebKit/UIProcess/cairo/BackingStoreCairo.cpp
index dc0a70b8824afdc7ec3dd1f69f4d9b51942924f6..4da6649c86b46dea36c2750802494ddb9b70cc24 100644
--- a/Source/WebKit/UIProcess/cairo/BackingStoreCairo.cpp
+++ b/Source/WebKit/UIProcess/cairo/BackingStoreCairo.cpp
@@ -27,9 +27,11 @@
 #include "config.h"
 #include "BackingStore.h"
 
+#include "DrawingAreaProxyCoordinatedGraphics.h"
 #include "ShareableBitmap.h"
 #include "UpdateInfo.h"
 #include "WebPageProxy.h"
+#include "WebPageInspectorController.h"
 #include <WebCore/BackingStoreBackendCairoImpl.h>
 #include <WebCore/CairoUtilities.h>
 #include <WebCore/GraphicsContextImplCairo.h>
@@ -72,6 +74,9 @@ void BackingStore::paint(cairo_t* context, const IntRect& rect)
     cairo_rectangle(context, rect.x(), rect.y(), rect.width(), rect.height());
     cairo_fill(context);
     cairo_restore(context);
+#if PLATFORM(GTK)
+    m_webPageProxy.inspectorController().didPaint(m_backend->surface());
+#endif
 }
 
 void BackingStore::incorporateUpdate(ShareableBitmap* bitmap, const UpdateInfo& updateInfo)
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/InspectorPlaywrightAgentClientGLib.cpp b/Source/WebKit/UIProcess/glib/InspectorPlaywrightAgentClientGLib.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..690cc1946b7d61aabaeca4a1013aaa0305339b76
--- /dev/null
+++ b/Source/WebKit/UIProcess/glib/InspectorPlaywrightAgentClientGLib.cpp
@@ -0,0 +1,152 @@
+/*
+ * 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 "InspectorPlaywrightAgentClientGLib.h"
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "InspectorPlaywrightAgent.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 {
+
+static WebCore::SoupNetworkProxySettings parseRawProxySettings(const String& proxyServer, const char* const* ignoreHosts)
+{
+    WebCore::SoupNetworkProxySettings settings;
+    if (proxyServer.isEmpty())
+        return settings;
+
+    settings.mode = WebCore::SoupNetworkProxySettings::Mode::Custom;
+    settings.defaultProxyURL = proxyServer.utf8();
+    settings.ignoreHosts.reset(g_strdupv(const_cast<char**>(ignoreHosts)));
+    return settings;
+}
+
+static WebCore::SoupNetworkProxySettings parseProxySettings(const String& proxyServer, const String& proxyBypassList)
+{
+    Vector<const char*> ignoreHosts;
+    if (!proxyBypassList.isEmpty()) {
+        Vector<String> tokens = proxyBypassList.split(',');
+        Vector<CString> protectTokens;
+        for (String token : tokens) {
+            CString cstr = token.utf8();
+            ignoreHosts.append(cstr.data());
+            protectTokens.append(WTFMove(cstr));
+        }
+    }
+    return parseRawProxySettings(proxyServer, ignoreHosts.data());
+}
+
+InspectorPlaywrightAgentClientGlib::InspectorPlaywrightAgentClientGlib(GMainLoop* mainLoop, const WTF::String& proxyURI, const char* const* ignoreHosts)
+    : m_mainLoop(mainLoop)
+    , m_proxySettings(parseRawProxySettings(proxyURI, ignoreHosts))
+{
+}
+
+RefPtr<WebPageProxy> InspectorPlaywrightAgentClientGlib::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 InspectorPlaywrightAgentClientGlib::closeBrowser()
+{
+    m_idToContext.clear();
+#if PLATFORM(GTK)
+    gtk_main_quit();
+#else
+    if (m_mainLoop)
+        g_main_loop_quit(m_mainLoop);
+#endif
+    if (webkitWebContextExistingCount() > 1)
+        fprintf(stderr, "LEAK: %d contexts are still alive when closing browser\n", webkitWebContextExistingCount());
+}
+
+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 InspectorPlaywrightAgentClientGlib::createBrowserContext(WTF::String& error, const WTF::String& proxyServer, const WTF::String& proxyBypassList)
+{
+    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));
+
+    if (!proxyServer.isEmpty()) {
+        WebCore::SoupNetworkProxySettings contextProxySettings = parseProxySettings(proxyServer, proxyBypassList);
+        browserContext.processPool->setNetworkProxySettings(contextProxySettings);
+    } else {
+        browserContext.processPool->setNetworkProxySettings(m_proxySettings);
+    }
+    return browserContext;
+}
+
+void InspectorPlaywrightAgentClientGlib::deleteBrowserContext(WTF::String& error, PAL::SessionID sessionID)
+{
+    m_idToContext.remove(sessionID);
+}
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/glib/InspectorPlaywrightAgentClientGLib.h b/Source/WebKit/UIProcess/glib/InspectorPlaywrightAgentClientGLib.h
new file mode 100644
index 0000000000000000000000000000000000000000..a073a77390b206deb794efe937df4f35d7198608
--- /dev/null
+++ b/Source/WebKit/UIProcess/glib/InspectorPlaywrightAgentClientGLib.h
@@ -0,0 +1,61 @@
+/*
+ * 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 "InspectorPlaywrightAgentClient.h"
+#include <WebCore/SoupNetworkProxySettings.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 InspectorPlaywrightAgentClientGlib : public InspectorPlaywrightAgentClient {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    InspectorPlaywrightAgentClientGlib(GMainLoop* mainLoop, const WTF::String& proxyURI, const char* const* ignoreHosts);
+    ~InspectorPlaywrightAgentClientGlib() override = default;
+
+    RefPtr<WebPageProxy> createPage(WTF::String& error, const BrowserContext&) override;
+    void closeBrowser() override;
+    BrowserContext createBrowserContext(WTF::String& error, const WTF::String& proxyServer, const WTF::String& proxyBypassList) 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;
+    WebCore::SoupNetworkProxySettings m_proxySettings;
+};
+
+} // namespace API
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/gtk/AcceleratedBackingStoreX11.cpp b/Source/WebKit/UIProcess/gtk/AcceleratedBackingStoreX11.cpp
index be19b6007c9c0fbfffb859e40fd34751493fe7d1..ce214fb7e22f8623aff6e2487cecd0272b21c478 100644
--- a/Source/WebKit/UIProcess/gtk/AcceleratedBackingStoreX11.cpp
+++ b/Source/WebKit/UIProcess/gtk/AcceleratedBackingStoreX11.cpp
@@ -31,6 +31,7 @@
 #include "DrawingAreaProxyCoordinatedGraphics.h"
 #include "LayerTreeContext.h"
 #include "WebPageProxy.h"
+#include "WebPageInspectorController.h"
 #include <WebCore/CairoUtilities.h>
 #include <WebCore/PlatformDisplayX11.h>
 #include <WebCore/XErrorTrapper.h>
@@ -256,6 +257,8 @@ bool AcceleratedBackingStoreX11::paint(cairo_t* cr, const IntRect& clipRect)
 
     cairo_restore(cr);
 
+    m_webPage.inspectorController().didPaint(m_surface.get());
+
     cairo_surface_flush(m_surface.get());
 
     return true;
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..d0f9827544994e450e24e3f7a427c35eeff94d67
--- /dev/null
+++ b/Source/WebKit/UIProcess/gtk/WebPageInspectorInputAgentGtk.cpp
@@ -0,0 +1,105 @@
+/*
+ * 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, const String& keyIdentifier, 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);
+    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);
+    }
+    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 3879abd15a643b0cbe266f9f521ba1e66def7d33..2efc4edc234266d26a15efc26a4e0d28937ca697 100644
--- a/Source/WebKit/UIProcess/ios/PageClientImplIOS.mm
+++ b/Source/WebKit/UIProcess/ios/PageClientImplIOS.mm
@@ -445,6 +445,8 @@ 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/InspectorPlaywrightAgentClientMac.h b/Source/WebKit/UIProcess/mac/InspectorPlaywrightAgentClientMac.h
new file mode 100644
index 0000000000000000000000000000000000000000..bce31b16fe37dc2a981389a6160e4094bf2b0f74
--- /dev/null
+++ b/Source/WebKit/UIProcess/mac/InspectorPlaywrightAgentClientMac.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 "InspectorPlaywrightAgentClient.h"
+#include <wtf/Forward.h>
+
+OBJC_PROTOCOL(_WKBrowserInspectorDelegate);
+
+namespace WebKit {
+
+class InspectorPlaywrightAgentClientMac : public InspectorPlaywrightAgentClient {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    InspectorPlaywrightAgentClientMac(_WKBrowserInspectorDelegate* delegate);
+    ~InspectorPlaywrightAgentClientMac() override = default;
+
+    RefPtr<WebPageProxy> createPage(WTF::String& error, const BrowserContext&) override;
+    void closeBrowser() override;
+    BrowserContext createBrowserContext(WTF::String& error, const WTF::String& proxyServer, const WTF::String& proxyBypassList) override;
+    void deleteBrowserContext(WTF::String& error, PAL::SessionID) override;
+
+private:
+    _WKBrowserInspectorDelegate* delegate_;
+};
+
+
+} // namespace API
diff --git a/Source/WebKit/UIProcess/mac/InspectorPlaywrightAgentClientMac.mm b/Source/WebKit/UIProcess/mac/InspectorPlaywrightAgentClientMac.mm
new file mode 100644
index 0000000000000000000000000000000000000000..600a1687094f5a209f24dc951206ba7faf4de991
--- /dev/null
+++ b/Source/WebKit/UIProcess/mac/InspectorPlaywrightAgentClientMac.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 "InspectorPlaywrightAgentClientMac.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 {
+
+InspectorPlaywrightAgentClientMac::InspectorPlaywrightAgentClientMac(_WKBrowserInspectorDelegate* delegate)
+  : delegate_(delegate)
+{
+}
+
+RefPtr<WebPageProxy> InspectorPlaywrightAgentClientMac::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 InspectorPlaywrightAgentClientMac::closeBrowser()
+{
+    [delegate_ quit];
+}
+
+BrowserContext InspectorPlaywrightAgentClientMac::createBrowserContext(WTF::String& error, const WTF::String& proxyServer, const WTF::String& proxyBypassList)
+{
+    _WKBrowserContext* wkBrowserContext = [[delegate_ createBrowserContext:proxyServer WithBypassList:proxyBypassList] autorelease];
+    BrowserContext browserContext;
+    browserContext.processPool = &static_cast<WebProcessPool&>([[wkBrowserContext processPool] _apiObject]);
+    browserContext.dataStore = &static_cast<WebsiteDataStore&>([[wkBrowserContext dataStore] _apiObject]);
+    return browserContext;
+}
+
+void InspectorPlaywrightAgentClientMac::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 53203c0bab7e8fc2f1b75d340c055c938590050e..207c96011155c51a398c3cb46b7beb3295990d5c 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();
 
@@ -154,6 +156,9 @@ private:
     void updateAcceleratedCompositingMode(const LayerTreeContext&) override;
     void didFirstLayerFlush(const LayerTreeContext&) override;
 
+// Paywright begin
+    RetainPtr<CGImageRef> takeSnapshotForAutomation() override;
+// Paywright end
     RefPtr<ViewSnapshot> takeViewSnapshot(Optional<WebCore::IntRect>&&) override;
     void wheelEventWasNotHandledByWebCore(const NativeWebWheelEvent&) override;
 #if ENABLE(MAC_GESTURE_EVENTS)
@@ -201,6 +206,10 @@ 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 7b7e66c79edaf84a8a14756524e16c26e57896c6..868c8bc1e3b74e3318c56e568a18d768bc8ccd27 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/RetainPtr.h>
 #import <wtf/text/CString.h>
@@ -103,6 +104,13 @@ 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)
@@ -156,6 +164,9 @@ NSWindow *PageClientImpl::activeWindow() const
 
 bool PageClientImpl::isViewWindowActive()
 {
+    if (_headless)
+        return true;
+
     ASSERT(hasProcessPrivilege(ProcessPrivilege::CanCommunicateWithWindowServer));
     NSWindow *activeViewWindow = activeWindow();
     return activeViewWindow.isKeyWindow || [NSApp keyWindow] == activeViewWindow;
@@ -163,6 +174,9 @@ 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)
@@ -186,6 +200,9 @@ void PageClientImpl::makeFirstResponder()
     
 bool PageClientImpl::isViewVisible()
 {
+    if (_headless)
+        return true;
+
     NSView *activeView = this->activeView();
     NSWindow *activeViewWindow = activeWindow();
 
@@ -269,7 +286,8 @@ void PageClientImpl::didRelaunchProcess()
 
 void PageClientImpl::preferencesDidChange()
 {
-    m_impl->preferencesDidChange();
+    if (m_impl)
+        m_impl->preferencesDidChange();
 }
 
 void PageClientImpl::toolTipChanged(const String& oldToolTip, const String& newToolTip)
@@ -445,6 +463,8 @@ IntRect PageClientImpl::rootViewToAccessibilityScreen(const IntRect& rect)
 
 void PageClientImpl::doneWithKeyEvent(const NativeWebKeyboardEvent& event, bool eventWasHandled)
 {
+    if (!event.nativeEvent())
+        return;
     m_impl->doneWithKeyEvent(event.nativeEvent(), eventWasHandled);
 }
 
@@ -562,6 +582,12 @@ CALayer *PageClientImpl::acceleratedCompositingRootLayer() const
     return m_impl->acceleratedCompositingRootLayer();
 }
 
+// Paywright begin
+RetainPtr<CGImageRef> PageClientImpl::takeSnapshotForAutomation() {
+    return m_impl->takeSnapshotForAutomation();
+}
+// Paywright begin
+
 RefPtr<ViewSnapshot> PageClientImpl::takeViewSnapshot(Optional<WebCore::IntRect>&&)
 {
     return m_impl->takeViewSnapshot();
@@ -740,6 +766,13 @@ 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);
@@ -906,6 +939,9 @@ 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..78bd14ef515e4022dbc251945d60248a791d50b3
--- /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"
+
+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, const String& keyIdentifier, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, OptionSet<WebEvent::Modifier> modifiers, Vector<String>& commands, WallTime timestamp)
+{
+    Vector<WebCore::KeypressCommand> macCommands;
+    for (const String& command : commands) {
+      m_page.registerKeypressCommandName(command);
+      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/InspectorPlaywrightAgentClientWin.cpp b/Source/WebKit/UIProcess/win/InspectorPlaywrightAgentClientWin.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..4e5910f0f1d1b237b7c5637ccbc4fe3f374ff391
--- /dev/null
+++ b/Source/WebKit/UIProcess/win/InspectorPlaywrightAgentClientWin.cpp
@@ -0,0 +1,90 @@
+/*
+ * 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 "InspectorPlaywrightAgentClientWin.h"
+
+#if ENABLE(REMOTE_INSPECTOR)
+
+#include "APIPageConfiguration.h"
+#include "APIProcessPoolConfiguration.h"
+#include "InspectorPlaywrightAgent.h"
+#include "WebPageProxy.h"
+#include "WebsiteDataStore.h"
+#include "WebPreferences.h"
+#include "WebProcessPool.h"
+#include "WebView.h"
+#include "WKAPICast.h"
+#include <WebCore/CurlProxySettings.h>
+#include <wtf/HashMap.h>
+#include <wtf/RefPtr.h>
+#include <wtf/text/StringView.h>
+#include <wtf/text/WTFString.h>
+
+namespace WebKit {
+
+InspectorPlaywrightAgentClientWin::InspectorPlaywrightAgentClientWin(ConfigureDataStoreCallback configureDataStore, CreatePageCallback createPage, QuitCallback quit)
+    : m_configureDataStore(configureDataStore)
+    , m_createPage(createPage)
+    , m_quit(quit)
+{
+}
+
+RefPtr<WebPageProxy> InspectorPlaywrightAgentClientWin::createPage(WTF::String& error, const BrowserContext& context)
+{
+    auto conf = API::PageConfiguration::create();
+    conf->setProcessPool(context.processPool.get());
+    conf->setWebsiteDataStore(context.dataStore.get());
+    return toImpl(m_createPage(toAPI(&conf.get())));
+}
+
+void InspectorPlaywrightAgentClientWin::closeBrowser()
+{
+    m_quit();
+}
+
+BrowserContext InspectorPlaywrightAgentClientWin::createBrowserContext(WTF::String& error, const WTF::String& proxyServer, const WTF::String& proxyBypassList)
+{
+    auto config = API::ProcessPoolConfiguration::create();
+    BrowserContext browserContext;
+    browserContext.processPool = WebKit::WebProcessPool::create(config);
+    browserContext.dataStore = WebKit::WebsiteDataStore::createNonPersistent();
+    m_configureDataStore(toAPI(browserContext.dataStore.get()));
+    if (!proxyServer.isEmpty()) {
+        URL proxyURL = URL(URL(), proxyServer);
+        WebCore::CurlProxySettings settings(WTFMove(proxyURL), String(proxyBypassList));
+        browserContext.dataStore->setNetworkProxySettings(WTFMove(settings));
+    }
+    PAL::SessionID sessionID = browserContext.dataStore->sessionID();
+    return browserContext;
+}
+
+void InspectorPlaywrightAgentClientWin::deleteBrowserContext(WTF::String& error, PAL::SessionID sessionID)
+{
+}
+
+} // namespace WebKit
+
+#endif // ENABLE(REMOTE_INSPECTOR)
diff --git a/Source/WebKit/UIProcess/win/InspectorPlaywrightAgentClientWin.h b/Source/WebKit/UIProcess/win/InspectorPlaywrightAgentClientWin.h
new file mode 100644
index 0000000000000000000000000000000000000000..e18db39e5e9fe3e70658b4596c636eac083222b4
--- /dev/null
+++ b/Source/WebKit/UIProcess/win/InspectorPlaywrightAgentClientWin.h
@@ -0,0 +1,60 @@
+/*
+ * 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 "InspectorPlaywrightAgentClient.h"
+#include <WebKit/WKInspector.h>
+#include <wtf/Forward.h>
+#include <wtf/text/StringHash.h>
+
+typedef void (*ConfigureDataStoreCallback)(WKWebsiteDataStoreRef dataStore);
+typedef WKPageRef (*CreatePageCallback)(WKPageConfigurationRef configuration);
+typedef void (*QuitCallback)();
+
+namespace WebKit {
+
+class InspectorPlaywrightAgentClientWin : public InspectorPlaywrightAgentClient {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    InspectorPlaywrightAgentClientWin(ConfigureDataStoreCallback, CreatePageCallback, QuitCallback);
+    ~InspectorPlaywrightAgentClientWin() override = default;
+
+    RefPtr<WebPageProxy> createPage(WTF::String& error, const BrowserContext&) override;
+    void closeBrowser() override;
+    BrowserContext createBrowserContext(WTF::String& error, const WTF::String& proxyServer, const WTF::String& proxyBypassList) override;
+    void deleteBrowserContext(WTF::String& error, PAL::SessionID) override;
+
+private:
+    ConfigureDataStoreCallback m_configureDataStore;
+    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..62b841fe1d0de2296e1c61e328cff564f5aa1c0f
--- /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_NOCOPYBITS | SWP_NOSENDCHANGING | 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..5cf8a010e9809e6a95741cdb7c2cbeb445ab638b
--- /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, const String& keyIdentifier, 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,
+        keyIdentifier,
+        windowsVirtualKeyCode,
+        nativeVirtualKeyCode,
+        isAutoRepeat,
+        isKeypad,
+        isSystemKey,
+        modifiers,
+        timestamp);
+    m_page.handleKeyboardEvent(event);
+}
+
+} // 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..c3d7cacea987ba2b094d5022c670705ef6ced129
--- /dev/null
+++ b/Source/WebKit/UIProcess/wpe/WebPageInspectorInputAgentWPE.cpp
@@ -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.
+ */
+
+#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, const String& keyIdentifier, 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,
+        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 e94fe6ecc22840e9f11a03ef12c247dfaa82c299..f0f692ca80c92b6eeec388cf6b1306865c937128 100644
--- a/Source/WebKit/WebKit.xcodeproj/project.pbxproj
+++ b/Source/WebKit/WebKit.xcodeproj/project.pbxproj
@@ -1779,6 +1779,18 @@
 		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 /* InspectorPlaywrightAgentClientMac.h in Headers */ = {isa = PBXBuildFile; fileRef = D71A94302370E025002C4D9E /* InspectorPlaywrightAgentClientMac.h */; };
+		D71A94342370E07A002C4D9E /* InspectorPlaywrightAgentClient.h in Headers */ = {isa = PBXBuildFile; fileRef = D71A94332370E07A002C4D9E /* InspectorPlaywrightAgentClient.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 /* InspectorPlaywrightAgentClientMac.mm in Sources */ = {isa = PBXBuildFile; fileRef = D7EB04E62372A73B00F744CE /* InspectorPlaywrightAgentClientMac.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 */; };
@@ -1832,6 +1844,7 @@
 		E5CB07DC20E1678F0022C183 /* WKFormColorControl.h in Headers */ = {isa = PBXBuildFile; fileRef = E5CB07DA20E1678F0022C183 /* WKFormColorControl.h */; };
 		ECA680D81E690E2500731D20 /* WebProcessCocoa.h in Headers */ = {isa = PBXBuildFile; fileRef = ECA680D71E690DF800731D20 /* WebProcessCocoa.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		ED82A7F2128C6FAF004477B3 /* WKBundlePageOverlay.h in Headers */ = {isa = PBXBuildFile; fileRef = 1A22F0FF1289FCD90085E74F /* WKBundlePageOverlay.h */; settings = {ATTRIBUTES = (Private, ); }; };
+		F3867F0A24607D4E008F0F31 /* InspectorScreencastAgent.h in Headers */ = {isa = PBXBuildFile; fileRef = F3867F0424607D2B008F0F31 /* InspectorScreencastAgent.h */; };
 		F409BA181E6E64BC009DA28E /* WKDragDestinationAction.h in Headers */ = {isa = PBXBuildFile; fileRef = F409BA171E6E64B3009DA28E /* WKDragDestinationAction.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		F42D634122A0EFDF00D2FB3A /* WebAutocorrectionData.h in Headers */ = {isa = PBXBuildFile; fileRef = F42D633F22A0EFD300D2FB3A /* WebAutocorrectionData.h */; };
 		F430E9422247335F005FE053 /* WebsiteMetaViewportPolicy.h in Headers */ = {isa = PBXBuildFile; fileRef = F430E941224732A9005FE053 /* WebsiteMetaViewportPolicy.h */; };
@@ -5253,6 +5266,19 @@
 		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 /* InspectorPlaywrightAgentClientMac.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = InspectorPlaywrightAgentClientMac.h; sourceTree = "<group>"; };
+		D71A94332370E07A002C4D9E /* InspectorPlaywrightAgentClient.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = InspectorPlaywrightAgentClient.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 /* InspectorPlaywrightAgentClientMac.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = InspectorPlaywrightAgentClientMac.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>"; };
@@ -5357,6 +5383,9 @@
 		ECA680D71E690DF800731D20 /* WebProcessCocoa.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = WebProcessCocoa.h; sourceTree = "<group>"; };
 		ECBFC1DB1E6A4D66000300C7 /* ExtraPublicSymbolsForTAPI.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = ExtraPublicSymbolsForTAPI.h; sourceTree = "<group>"; };
 		F036978715F4BF0500C3A80E /* WebColorPicker.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = WebColorPicker.cpp; sourceTree = "<group>"; };
+		F3867F0324607D2B008F0F31 /* InspectorScreencastAgent.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = InspectorScreencastAgent.cpp; sourceTree = "<group>"; };
+		F3867F0424607D2B008F0F31 /* InspectorScreencastAgent.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = InspectorScreencastAgent.h; sourceTree = "<group>"; };
+		F3A1D2F72460E68400AA3AB8 /* InspectorScreencastAgentMac.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = InspectorScreencastAgentMac.mm; sourceTree = "<group>"; };
 		F409BA171E6E64B3009DA28E /* WKDragDestinationAction.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WKDragDestinationAction.h; sourceTree = "<group>"; };
 		F40D1B68220BDC0F00B49A01 /* WebAutocorrectionContext.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; name = WebAutocorrectionContext.h; path = ios/WebAutocorrectionContext.h; sourceTree = "<group>"; };
 		F41056612130699A0092281D /* APIAttachmentCocoa.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = APIAttachmentCocoa.mm; sourceTree = "<group>"; };
@@ -7186,6 +7215,7 @@
 		37C4C08318149C2A003688B9 /* Cocoa */ = {
 			isa = PBXGroup;
 			children = (
+				D71A94492372290B002C4D9E /* _WKBrowserInspector.h */,
 				1A43E826188F38E2009E4D30 /* Deprecated */,
 				37A5E01218BBF937000A081E /* _WKActivatedElementInfo.h */,
 				37A5E01118BBF937000A081E /* _WKActivatedElementInfo.mm */,
@@ -8483,6 +8513,8 @@
 			children = (
 				9197940423DBC4BB00257892 /* InspectorBrowserAgent.cpp */,
 				9197940323DBC4BB00257892 /* InspectorBrowserAgent.h */,
+				F3867F0324607D2B008F0F31 /* InspectorScreencastAgent.cpp */,
+				F3867F0424607D2B008F0F31 /* InspectorScreencastAgent.h */,
 			);
 			path = Agents;
 			sourceTree = "<group>";
@@ -8490,6 +8522,7 @@
 		91D970D623DA6D550057DBC3 /* mac */ = {
 			isa = PBXGroup;
 			children = (
+				F3A1D2F72460E68400AA3AB8 /* InspectorScreencastAgentMac.mm */,
 				A5D3504D1D78F0D2005124A9 /* RemoteWebInspectorProxyMac.mm */,
 				1CA8B935127C774E00576C2B /* WebInspectorProxyMac.mm */,
 				994BADF11F7D77EA00B571E7 /* WKInspectorViewController.h */,
@@ -8916,6 +8949,12 @@
 		BC032DC310F438260058C15A /* UIProcess */ = {
 			isa = PBXGroup;
 			children = (
+				D76D6887238DBD80008D314B /* InspectorDialogAgent.h */,
+				D71A944B237239FB002C4D9E /* BrowserInspectorPipe.h */,
+				D71A943F2371F67E002C4D9E /* WebPageInspectorEmulationAgent.h */,
+				D71A94402371F67E002C4D9E /* WebPageInspectorInputAgent.h */,
+				D71A94392370F060002C4D9E /* RemoteInspectorPipe.h */,
+				D71A94332370E07A002C4D9E /* InspectorPlaywrightAgentClient.h */,
 				BC032DC410F4387C0058C15A /* API */,
 				512F588D12A8836F00629530 /* Authentication */,
 				9955A6E81C79809000EB6A93 /* Automation */,
@@ -9196,6 +9235,7 @@
 		BC0C376610F807660076D7CB /* C */ = {
 			isa = PBXGroup;
 			children = (
+				D71A942C2370DF81002C4D9E /* WKBrowserInspector.h */,
 				5123CF18133D25E60056F800 /* cg */,
 				6EE849C41368D9040038D481 /* mac */,
 				BCB63477116BF10600603215 /* WebKit2_C.h */,
@@ -9796,6 +9836,11 @@
 		BCCF085C113F3B7500C650C5 /* mac */ = {
 			isa = PBXGroup;
 			children = (
+				D7EB04E62372A73B00F744CE /* InspectorPlaywrightAgentClientMac.mm */,
+				D71A94302370E025002C4D9E /* InspectorPlaywrightAgentClientMac.h */,
+				D79902AE236E9404005D6F7E /* WebPageInspectorEmulationAgentMac.mm */,
+				D79902B0236E9404005D6F7E /* WebPageInspectorInputAgentMac.mm */,
+				D79902AF236E9404005D6F7E /* InspectorTargetProxyMac.mm */,
 				B878B613133428DC006888E9 /* CorrectionPanel.h */,
 				B878B614133428DC006888E9 /* CorrectionPanel.mm */,
 				C1817362205844A900DFDA65 /* DisplayLink.cpp */,
@@ -10578,6 +10623,7 @@
 				991F492F23A812C60054642B /* _WKInspectorDebuggableInfo.h in Headers */,
 				99036AE223A949CF0000B06A /* _WKInspectorDebuggableInfoInternal.h in Headers */,
 				9197940C23DBC50300257892 /* _WKInspectorDelegate.h in Headers */,
+				D71A944A2372290B002C4D9E /* _WKBrowserInspector.h in Headers */,
 				5CAFDE472130846A00B1F7E1 /* _WKInspectorInternal.h in Headers */,
 				9979CA58237F49F10039EC05 /* _WKInspectorPrivate.h in Headers */,
 				A5C0F0AB2000658200536536 /* _WKInspectorWindow.h in Headers */,
@@ -10830,6 +10876,7 @@
 				BC06F43A12DBCCFB002D78DE /* GeolocationPermissionRequestProxy.h in Headers */,
 				2DA944A41884E4F000ED86DB /* GestureTypes.h in Headers */,
 				2DA049B8180CCD0A00AAFA9E /* GraphicsLayerCARemote.h in Headers */,
+				D71A94342370E07A002C4D9E /* InspectorPlaywrightAgentClient.h in Headers */,
 				C0CE72AD1247E78D00BC0EC4 /* HandleMessage.h in Headers */,
 				1AC75A1B1B3368270056745B /* HangDetectionDisabler.h in Headers */,
 				57AC8F50217FEED90055438C /* HidConnection.h in Headers */,
@@ -10958,8 +11005,10 @@
 				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 */,
@@ -11043,6 +11092,7 @@
 				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 */,
 				1A0C227E2451130A00ED614D /* QuickLookThumbnailingSoftLink.h in Headers */,
@@ -11339,6 +11389,7 @@
 				A543E30D215C8A9000279CD9 /* WebPageInspectorTargetController.h in Headers */,
 				A543E307215AD13700279CD9 /* WebPageInspectorTargetFrontendChannel.h in Headers */,
 				C0CE72A11247E71D00BC0EC4 /* WebPageMessages.h in Headers */,
+				F3867F0A24607D4E008F0F31 /* InspectorScreencastAgent.h in Headers */,
 				2D5C9D0619C81D8F00B3C5C1 /* WebPageOverlay.h in Headers */,
 				46C392292316EC4D008EED9B /* WebPageProxyIdentifier.h in Headers */,
 				BCBD3915125BB1A800D2C29F /* WebPageProxyMessages.h in Headers */,
@@ -11470,6 +11521,7 @@
 				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 */,
@@ -11522,6 +11574,7 @@
 				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 */,
@@ -11672,6 +11725,7 @@
 				1AB8A1F818400BB800E9AE69 /* WKPageContextMenuClient.h in Headers */,
 				8372DB251A674C8F00C697C5 /* WKPageDiagnosticLoggingClient.h in Headers */,
 				1AB8A1F418400B8F00E9AE69 /* WKPageFindClient.h in Headers */,
+				D71A94322370E025002C4D9E /* InspectorPlaywrightAgentClientMac.h in Headers */,
 				1AB8A1F618400B9D00E9AE69 /* WKPageFindMatchesClient.h in Headers */,
 				1AB8A1F018400B0000E9AE69 /* WKPageFormClient.h in Headers */,
 				BC7B633712A45ABA00D174A4 /* WKPageGroup.h in Headers */,
@@ -12731,6 +12785,7 @@
 				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 */,
@@ -12742,6 +12797,7 @@
 				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 */,
@@ -12766,6 +12822,7 @@
 				1A2D8439127F65D5001EB962 /* NPObjectMessageReceiverMessageReceiver.cpp in Sources */,
 				2D92A792212B6AD400F493FD /* NPObjectProxy.cpp in Sources */,
 				2D92A793212B6AD400F493FD /* NPRemoteObjectMap.cpp in Sources */,
+				D7EB04E72372A73B00F744CE /* InspectorPlaywrightAgentClientMac.mm in Sources */,
 				2D913447212CF9F000128AFD /* NPRuntimeObjectMap.cpp in Sources */,
 				2D913448212CF9F000128AFD /* NPRuntimeUtilities.cpp in Sources */,
 				2D92A794212B6AD400F493FD /* NPVariantData.cpp in Sources */,
@@ -13049,6 +13106,7 @@
 				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 0ddb35334438784fb216fdf7108429726f2c6667..bd2cb327223291543272b0636f834a24e08412d3 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>
@@ -226,8 +227,24 @@ 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;
     }
@@ -758,7 +775,7 @@ 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)
@@ -769,6 +786,11 @@ void WebLoaderStrategy::addOnlineStateChangeListener(Function<void(bool)>&& list
 
 void WebLoaderStrategy::setOnLineState(bool isOnLine)
 {
+    if (m_emulateOfflineState) {
+        m_isOnLine = isOnLine;
+        return;
+    }
+
     if (m_isOnLine == isOnLine)
         return;
 
@@ -777,6 +799,12 @@ 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 283afab34d2d73235219f9aad80f6028a9b6faef..bbe4f258383dc21574cc3b5769deae721d5f427d 100644
--- a/Source/WebKit/WebProcess/Network/WebLoaderStrategy.h
+++ b/Source/WebKit/WebProcess/Network/WebLoaderStrategy.h
@@ -88,6 +88,7 @@ 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);
@@ -126,6 +127,7 @@ private:
     HashMap<unsigned long, PreconnectCompletionHandler> m_preconnectCompletionHandlers;
     Vector<Function<void(bool)>> m_onlineStateChangeListeners;
     bool m_isOnLine { true };
+    bool m_emulateOfflineState { false };
 };
 
 } // namespace WebKit
diff --git a/Source/WebKit/WebProcess/WebCoreSupport/WebChromeClient.cpp b/Source/WebKit/WebProcess/WebCoreSupport/WebChromeClient.cpp
index 22f9c46ecdf08834321840ffe71a5114616a3357..cf551cd6111e86421e7311c403715d62917abe25 100644
--- a/Source/WebKit/WebProcess/WebCoreSupport/WebChromeClient.cpp
+++ b/Source/WebKit/WebProcess/WebCoreSupport/WebChromeClient.cpp
@@ -385,6 +385,8 @@ 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);
 }
@@ -775,6 +777,13 @@ bool WebChromeClient::canShowDataListSuggestionLabels() const
 
 #endif
 
+#if ENABLE(ORIENTATION_EVENTS) && !PLATFORM(IOS_FAMILY)
+int WebChromeClient::deviceOrientation() const {
+    // Only overrides are supported for non-iOS platforms.
+    return 0;
+}
+#endif
+
 void WebChromeClient::runOpenPanel(Frame& frame, FileChooser& fileChooser)
 {
     if (m_page.activeOpenPanelResultListener())
diff --git a/Source/WebKit/WebProcess/WebCoreSupport/WebFrameLoaderClient.cpp b/Source/WebKit/WebProcess/WebCoreSupport/WebFrameLoaderClient.cpp
index 0587c38861b0b77beaa9dcc911895305e4fa155e..3b89b5dd5fedc50d108a0fb539ea4a41f0d12159 100644
--- a/Source/WebKit/WebProcess/WebCoreSupport/WebFrameLoaderClient.cpp
+++ b/Source/WebKit/WebProcess/WebCoreSupport/WebFrameLoaderClient.cpp
@@ -1538,13 +1538,6 @@ void WebFrameLoaderClient::transitionToCommittedForNewPage()
     if (webPage->scrollPinningBehavior() != DoNotPin)
         view->setScrollPinningBehavior(webPage->scrollPinningBehavior());
 
-#if USE(COORDINATED_GRAPHICS)
-    if (shouldUseFixedLayout) {
-        view->setDelegatesScrolling(shouldUseFixedLayout);
-        view->setPaintsEntireContents(shouldUseFixedLayout);
-        return;
-    }
-#endif
 }
 
 void WebFrameLoaderClient::didRestoreFromBackForwardCache()
diff --git a/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp b/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp
index 564126e14e22882e7896fcff3e6d32f722eec47b..fabaad5041e55ab49e7a3bc4a746406caf5759ad 100644
--- a/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp
+++ b/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp
@@ -37,6 +37,7 @@
 #include "WebPreferencesKeys.h"
 #include <WebCore/Frame.h>
 #include <WebCore/GraphicsContext.h>
+#include <WebCore/InspectorController.h>
 #include <WebCore/Page.h>
 #include <WebCore/PageOverlayController.h>
 #include <WebCore/Settings.h>
@@ -122,6 +123,16 @@ void DrawingAreaCoordinatedGraphics::scroll(const IntRect& scrollRect, const Int
         ASSERT(m_scrollRect.isEmpty());
         ASSERT(m_scrollOffset.isEmpty());
         ASSERT(m_dirtyRegion.isEmpty());
+// Playwright begin
+#if !PLATFORM(WIN)
+        if (m_webPage.mainFrameView() && m_webPage.mainFrameView()->useFixedLayout()) {
+            IntRect visibleRect;
+            visibleRect.move(-scrollDelta.width(), -scrollDelta.height());
+            m_layerTreeHost->scrollNonCompositedContents(visibleRect);
+            return;
+        }
+#endif
+// Playwright end
         m_layerTreeHost->scrollNonCompositedContents(scrollRect);
         return;
     }
@@ -247,6 +258,7 @@ void DrawingAreaCoordinatedGraphics::updatePreferences(const WebPreferencesStore
         settings.setAcceleratedCompositingEnabled(false);
     }
 #endif
+
     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.
@@ -716,6 +728,11 @@ void DrawingAreaCoordinatedGraphics::display()
         return;
     }
 
+// Playwright begin
+#if PLATFORM(WPE) || PLATFORM(WIN)
+    m_webPage.corePage()->inspectorController().willDisplay();
+#endif
+// Playwright end
     send(Messages::DrawingAreaProxy::Update(m_backingStoreStateID, updateInfo));
     m_isWaitingForDidUpdate = true;
 }
diff --git a/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/LayerTreeHost.cpp b/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/LayerTreeHost.cpp
index 8685e23d0d468601c459954775fe6f565b0ce7ac..f9d49292837bf390b81eadeaebe2d4d599bc236c 100644
--- a/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/LayerTreeHost.cpp
+++ b/Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/LayerTreeHost.cpp
@@ -166,8 +166,16 @@ void LayerTreeHost::setViewOverlayRootLayer(GraphicsLayer* viewOverlayRootLayer)
 void LayerTreeHost::scrollNonCompositedContents(const IntRect& rect)
 {
     auto* frameView = m_webPage.mainFrameView();
+
+// Playwright begin
+#if PLATFORM(WIN)
     if (!frameView || !frameView->delegatesScrolling())
+        return
+#else
+    if (!frameView)
         return;
+#endif
+// Playwright end
 
     m_viewportController.didScroll(rect.location());
     if (m_isDiscardable)
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 0965d2c00720e1570331d30e108e5e1dbab35591..89aea1f3fb9b712c272fb9b96f9777f8a8a1aef0 100644
--- a/Source/WebKit/WebProcess/WebPage/WebPage.cpp
+++ b/Source/WebKit/WebProcess/WebPage/WebPage.cpp
@@ -773,6 +773,9 @@ WebPage::WebPage(PageIdentifier pageID, WebPageCreationParameters&& parameters)
     send(Messages::WebPageProxy::DidCreateContextForVisibilityPropagation(m_contextForVisibilityPropagation->contextID()));
 #endif
 
+    if (parameters.shouldPauseInInspectorWhenShown)
+        m_page->inspectorController().pauseWhenShown();
+
     updateThrottleState();
 }
 
@@ -1532,6 +1535,22 @@ 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 };
+    frame->coreFrame()->loader().load(WTFMove(frameLoadRequest));
+    ASSERT(!m_pendingFrameNavigationID);
+}
+
 void WebPage::loadRequest(LoadParameters&& loadParameters)
 {
     setIsNavigatingToAppBoundDomain(loadParameters.isNavigatingToAppBoundDomain);
@@ -1738,17 +1757,13 @@ 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())
@@ -1765,20 +1780,18 @@ 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));
@@ -1786,7 +1799,6 @@ void WebPage::sendViewportAttributesChanged(const ViewportArguments& viewportArg
     send(Messages::WebPageProxy::DidChangeViewportProperties(attr));
 #endif
 }
-#endif
 
 void WebPage::scrollMainFrameIfNotAtMaxScrollPosition(const IntSize& scrollOffset)
 {
@@ -2085,6 +2097,7 @@ void WebPage::scaleView(double scale)
     }
 
     m_page->setViewScaleFactor(scale);
+    send(Messages::WebPageProxy::ViewScaleFactorDidChange(scale));
     scalePage(pageScale, scrollPositionAtNewScale);
 }
 
@@ -2189,17 +2202,13 @@ 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)
@@ -3084,6 +3093,11 @@ 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();
@@ -3324,6 +3338,7 @@ void WebPage::didCompletePageTransition()
 void WebPage::show()
 {
     send(Messages::WebPageProxy::ShowPage());
+    m_page->inspectorController().didShowNewWindow();
 }
 
 void WebPage::setShouldFireEvents(bool shouldFireEvents)
@@ -6419,6 +6434,9 @@ 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 0495602f0e36506fd3a686984423f8222c74b926..0db6e61f8730a7a1cfbc64fcdc65466ec52c2497 100644
--- a/Source/WebKit/WebProcess/WebPage/WebPage.h
+++ b/Source/WebKit/WebProcess/WebPage/WebPage.h
@@ -1167,6 +1167,7 @@ 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();
 
@@ -1436,6 +1437,7 @@ 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&&);
@@ -1588,9 +1590,7 @@ 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);
@@ -2057,6 +2057,7 @@ 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 16af317e8846f5f3f96c080b4caa875a6a4000d4..989727ac97daf431a620c295b4ce23010d528607 100644
--- a/Source/WebKit/WebProcess/WebPage/WebPage.messages.in
+++ b/Source/WebKit/WebProcess/WebPage/WebPage.messages.in
@@ -133,6 +133,7 @@ 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);
@@ -173,6 +174,7 @@ 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 ab9cbad18e02f5da3e03ce0c58e46ee7a22739ed..4cfb84a209c855efe6c229e67178d178a732682d 100644
--- a/Source/WebKit/WebProcess/WebProcess.cpp
+++ b/Source/WebKit/WebProcess/WebProcess.cpp
@@ -81,6 +81,7 @@
 #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>
@@ -284,6 +285,8 @@ 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 9fcd43bd1fe68d96674f90ccb974bbe3312c01f9..330921f916ead6b0ddac45ed24df16b4ef6334a7 100644
--- a/Source/WebKitLegacy/mac/WebView/WebHTMLView.mm
+++ b/Source/WebKitLegacy/mac/WebView/WebHTMLView.mm
@@ -4214,7 +4214,7 @@ 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 299cb1ca7934ba8aaa3d620cf61594be640b039a..f768038894b2fac417e20467dcebca85c6e2c06b 100644
--- a/Source/WebKitLegacy/mac/WebView/WebView.mm
+++ b/Source/WebKitLegacy/mac/WebView/WebView.mm
@@ -4494,7 +4494,7 @@ IGNORE_WARNINGS_END
 }
 #endif // PLATFORM(IOS_FAMILY)
 
-#if ENABLE(TOUCH_EVENTS)
+#if ENABLE(IOS_TOUCH_EVENTS)
 
 - (NSArray *)_touchEventRegions
 {
@@ -4536,7 +4536,7 @@ IGNORE_WARNINGS_END
     }).autorelease();
 }
 
-#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/FindLibVPX.cmake b/Source/cmake/FindLibVPX.cmake
new file mode 100644
index 0000000000000000000000000000000000000000..dd6a53e2d57318489b7e49dd7373706d5d9dc387
--- /dev/null
+++ b/Source/cmake/FindLibVPX.cmake
@@ -0,0 +1,25 @@
+# Find LibVPX
+
+find_package(PkgConfig QUIET)
+pkg_check_modules(PC_LIBVPX REQUIRED vpx)
+
+find_path(LIBVPX_INCLUDE_DIRS
+    NAMES vpx/vp8.h
+    HINTS ${PC_LIBVPX_INCLUDEDIR}
+          ${PC_LIBVPX_INCLUDE_DIRS}
+)
+
+find_library(LIBVPX_LIBRARIES
+    NAMES vpx
+    HINTS ${PC_LIBVPX_LIBDIR}
+          ${PC_LIBVPX_LIBRARY_DIRS}
+)
+
+include(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(LibVPX REQUIRED_VARS LIBVPX_INCLUDE_DIRS LIBVPX_LIBRARIES
+                                         VERSION_VAR   PC_LIBVPX_VERSION)
+
+mark_as_advanced(
+    LIBVPX_INCLUDE_DIRS
+    LIBVPX_LIBRARIES
+)
diff --git a/Source/cmake/OptionsGTK.cmake b/Source/cmake/OptionsGTK.cmake
index a3e5519e987e8840d9a86b296a31e247e920b1c3..483c06a6a04c37d4f0a4048c64fbe544ba4eac4a 100644
--- a/Source/cmake/OptionsGTK.cmake
+++ b/Source/cmake/OptionsGTK.cmake
@@ -6,6 +6,8 @@ WEBKIT_OPTION_DEFINE(USE_GTK4 "Whether to enable usage of GTK4 instead of GTK3."
 
 SET_PROJECT_VERSION(2 29 1)
 
+set(ENABLE_WEBKIT_LEGACY OFF)
+
 if (USE_GTK4)
     set(WEBKITGTK_API_VERSION 5.0)
     set(GTK_MINIMUM_VERSION 3.98.5)
@@ -55,6 +57,10 @@ find_package(EGL)
 find_package(OpenGL)
 find_package(OpenGLES2)
 
+# Playwright begin
+find_package(LibVPX REQUIRED)
+# Playwright end
+
 include(GStreamerDefinitions)
 
 SET_AND_EXPOSE_TO_BUILD(USE_ATK TRUE)
@@ -198,6 +204,13 @@ if (USE_GTK4)
 WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_NETSCAPE_PLUGIN_API PRIVATE OFF)
 endif ()
 
+# 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 1e32f16e9d2cb73f267ceb19c6aed46236b81587..2d1440b013ff6d7ada5bb76b7063da8d5d925214 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)
 
@@ -76,13 +77,21 @@ WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_WEBGL2 PRIVATE OFF)
 WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_WEB_RTC PRIVATE ${ENABLE_EXPERIMENTAL_FEATURES})
 WEBKIT_OPTION_DEFAULT_PORT_VALUE(ENABLE_WEBXR PRIVATE ${ENABLE_EXPERIMENTAL_FEATURES})
 
+# 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.
 WEBKIT_OPTION_DEFINE(ENABLE_GTKDOC "Whether or not to use generate gtkdoc." PUBLIC OFF)
 WEBKIT_OPTION_DEFINE(USE_OPENJPEG "Whether to enable support for JPEG2000 images." PUBLIC ON)
 WEBKIT_OPTION_DEFINE(USE_WOFF2 "Whether to enable support for WOFF2 Web Fonts." PUBLIC ON)
-WEBKIT_OPTION_DEFINE(ENABLE_WPE_QT_API "Whether to enable support for the Qt5/QML plugin" PUBLIC ${DEVELOPER_MODE})
+WEBKIT_OPTION_DEFINE(ENABLE_WPE_QT_API "Whether to enable support for the Qt5/QML plugin" PUBLIC OFF)
 WEBKIT_OPTION_DEFINE(USE_SYSTEMD "Whether to enable journald logging" PUBLIC ON)
 
 # Private options specific to the WPE port.
diff --git a/Source/cmake/OptionsWin.cmake b/Source/cmake/OptionsWin.cmake
index 4047a1d6df94f3c57337875c390eae447bcfc3ea..7fb9b0927ce187fc060ae84408b5130351f45520 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 ()
 
@@ -91,6 +92,13 @@ 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_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 3845eabba3e964f9e11bb0ffcb8726fd4ea96fc4..630a6e395298bd9c03c1b131f984b0a8444d2051 100644
--- a/Tools/MiniBrowser/gtk/BrowserTab.c
+++ b/Tools/MiniBrowser/gtk/BrowserTab.c
@@ -160,6 +160,11 @@ static void loadChanged(WebKitWebView *webView, WebKitLoadEvent loadEvent, Brows
 #endif
 }
 
+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);
@@ -623,6 +628,7 @@ 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 15d805bd0c7cdeceefcd3f77f6e363fc1643ac18..304f43c2220324403f5f4f0f4896106593242564 100644
--- a/Tools/MiniBrowser/gtk/BrowserWindow.c
+++ b/Tools/MiniBrowser/gtk/BrowserWindow.c
@@ -1309,6 +1309,12 @@ static gboolean browserWindowDeleteEvent(GtkWidget *widget, GdkEventAny* event)
 }
 #endif
 
+static void zeroPreferredSize(GtkWidget* widget, gint* minimumSize, gint* naturalSize)
+{
+    *minimumSize = 10;
+    *naturalSize = 10;
+}
+
 static void browser_window_class_init(BrowserWindowClass *klass)
 {
     GObjectClass *gobjectClass = G_OBJECT_CLASS(klass);
@@ -1322,6 +1328,14 @@ static void browser_window_class_init(BrowserWindowClass *klass)
     GtkWidgetClass *widgetClass = GTK_WIDGET_CLASS(klass);
     widgetClass->delete_event = browserWindowDeleteEvent;
 #endif
+
+// Playwrigth begin
+    // Override preferred (which is minimum :-) size to 0 so that we can
+    // emulate arbitrary resolution.
+    GtkWidgetClass* browserWidgetClass = GTK_WIDGET_CLASS(klass);
+    browserWidgetClass->get_preferred_width = zeroPreferredSize;
+    browserWidgetClass->get_preferred_height = zeroPreferredSize;
+// Playwrigth end
 }
 
 /* Public API. */
diff --git a/Tools/MiniBrowser/gtk/BrowserWindow.h b/Tools/MiniBrowser/gtk/BrowserWindow.h
index 62629b4c1c25ae82bd797b39bbf9de0331f8eed2..5de7900a29b0e629f1ac404bbb0dc5b4e605294d 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;
diff --git a/Tools/MiniBrowser/gtk/main.c b/Tools/MiniBrowser/gtk/main.c
index 0b236620d9c70b4b94e280ca508113c857d75832..cb26e5bbcd5614fdaad88282f3bec8884bada31e 100644
--- a/Tools/MiniBrowser/gtk/main.c
+++ b/Tools/MiniBrowser/gtk/main.c
@@ -53,7 +53,12 @@ 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;
+static GtkApplication *browserApplication = NULL;
 
 typedef enum {
     MINI_BROWSER_ERROR_INVALID_ABOUT_PATH
@@ -121,6 +126,10 @@ 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 }
 };
@@ -500,6 +509,35 @@ 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);
+    gtk_window_set_application(GTK_WINDOW(newWindow), browserApplication);
+    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, proxy, ignoreHosts);
+}
+
 static void startup(GApplication *application)
 {
     const char *actionAccels[] = {
@@ -530,12 +568,31 @@ static void startup(GApplication *application)
 
 static void activate(GApplication *application, WebKitSettings *webkitSettings)
 {
-    WebKitWebsiteDataManager *manager = (privateMode || automationMode) ? webkit_website_data_manager_new_ephemeral() : webkit_website_data_manager_new(NULL);
+    if (inspectorPipe)
+        configureBrowserInspectorPipe();
+
+    if (noStartupWindow) {
+        gtk_main();
+        g_clear_object(&webkitSettings);
+        return;
+    }
+
+    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,
 #if !GTK_CHECK_VERSION(3, 98, 0)
         "use-system-appearance-for-scrollbars", FALSE,
 #endif
         NULL);
+    persistentWebContext = webContext;
     g_object_unref(manager);
 
     if (cookiesPolicy) {
@@ -554,7 +611,7 @@ static void activate(GApplication *application, WebKitSettings *webkitSettings)
     }
 
     if (proxy) {
-        WebKitNetworkProxySettings *webkitProxySettings = webkit_network_proxy_settings_new(proxy, ignoreHosts);
+        WebKitNetworkProxySettings* webkitProxySettings = webkit_network_proxy_settings_new(proxy, ignoreHosts);
         webkit_web_context_set_network_proxy_settings(webContext, WEBKIT_NETWORK_PROXY_MODE_CUSTOM, webkitProxySettings);
         webkit_network_proxy_settings_free(webkitProxySettings);
     }
@@ -616,9 +673,7 @@ static void activate(GApplication *application, WebKitSettings *webkitSettings)
             WebKitWebView *webView = createBrowserTab(mainWindow, webkitSettings, userContentManager);
             if (!i)
                 firstTab = GTK_WIDGET(webView);
-            gchar *url = argumentToURL(uriArguments[i]);
-            webkit_web_view_load_uri(webView, url);
-            g_free(url);
+            webkit_web_view_load_uri(webView, uriArguments[i]);
         }
     } else {
         WebKitWebView *webView = createBrowserTab(mainWindow, webkitSettings, userContentManager);
@@ -692,9 +747,11 @@ int main(int argc, char *argv[])
     }
 
     GtkApplication *application = gtk_application_new(NULL, G_APPLICATION_FLAGS_NONE);
+    browserApplication = application;
     g_signal_connect(application, "startup", G_CALLBACK(startup), NULL);
     g_signal_connect(application, "activate", G_CALLBACK(activate), webkitSettings);
     g_application_run(G_APPLICATION(application), 0, NULL);
+    browserApplication = NULL;
     g_object_unref(application);
 
     return 0;
diff --git a/Tools/MiniBrowser/wpe/main.cpp b/Tools/MiniBrowser/wpe/main.cpp
index fde24a7cc8ceb8cc6d7810e3548a5129d1c0a187..3f993c33069b063f6f2446e9503b9f095974ee0f 100644
--- a/Tools/MiniBrowser/wpe/main.cpp
+++ b/Tools/MiniBrowser/wpe/main.cpp
@@ -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;
@@ -64,6 +67,9 @@ 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 }
 };
@@ -148,13 +154,34 @@ static void filterSavedCallback(WebKitUserContentFilterStore *store, GAsyncResul
     g_main_loop_quit(data->mainLoop);
 }
 
+static gboolean webViewLoadFailed()
+{
+    return TRUE;
+}
+
 static void webViewClose(WebKitWebView* webView, gpointer)
 {
     // Hash table key delete func takes care of unref'ing the view
     g_hash_table_remove(openViews, 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();
@@ -166,17 +193,59 @@ 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));
+// Playwright begin
+    if (headlessMode) {
+        webkit_web_view_backend_set_screenshot_callback(viewBackend,
+            [](gpointer data) {
+                return static_cast<WPEToolingBackends::HeadlessViewBackend*>(data)->snapshot();
+            });
+    }
+// Playwright end
+    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, "create", G_CALLBACK(createWebView), nullptr);
     g_signal_connect(newWebView, "close", G_CALLBACK(webViewClose), nullptr);
 
     g_hash_table_add(openViews, newWebView);
 
+    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,  proxy, ignoreHosts);
+}
+
 int main(int argc, char *argv[])
 {
 #if ENABLE_DEVELOPER_MODE
@@ -211,6 +280,16 @@ int main(int argc, char *argv[])
     }
 
     auto* loop = g_main_loop_new(nullptr, FALSE);
+    if (inspectorPipe)
+        configureBrowserInspector(loop);
+
+    openViews = g_hash_table_new_full(nullptr, nullptr, g_object_unref, nullptr);
+
+    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();
@@ -220,7 +299,19 @@ 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);
@@ -238,7 +329,7 @@ int main(int argc, char *argv[])
     }
 
     if (proxy) {
-        auto* webkitProxySettings = webkit_network_proxy_settings_new(proxy, ignoreHosts);
+        WebKitNetworkProxySettings* webkitProxySettings = webkit_network_proxy_settings_new(proxy, ignoreHosts);
         webkit_web_context_set_network_proxy_settings(webContext, WEBKIT_NETWORK_PROXY_MODE_CUSTOM, webkitProxySettings);
         webkit_network_proxy_settings_free(webkitProxySettings);
     }
@@ -284,7 +375,14 @@ int main(int argc, char *argv[])
     auto* viewBackend = webkit_web_view_backend_new(wpeBackend, [](gpointer data) {
         delete static_cast<WPEToolingBackends::ViewBackend*>(data);
     }, backend.release());
-
+// Playwright begin
+    if (headlessMode) {
+        webkit_web_view_backend_set_screenshot_callback(viewBackend,
+            [](gpointer data) {
+                return static_cast<WPEToolingBackends::HeadlessViewBackend*>(data)->snapshot();
+            });
+    }
+// Playwright end
     auto* webView = WEBKIT_WEB_VIEW(g_object_new(WEBKIT_TYPE_WEB_VIEW,
         "backend", viewBackend,
         "web-context", webContext,
@@ -301,8 +399,6 @@ int main(int argc, char *argv[])
         backendPtr->setAccessibleChild(ATK_OBJECT(accessible));
 #endif
 
-    openViews = g_hash_table_new_full(nullptr, nullptr, g_object_unref, nullptr);
-
     webkit_web_context_set_automation_allowed(webContext, automationMode);
     g_signal_connect(webContext, "automation-started", G_CALLBACK(automationStartedCallback), webView);
     g_signal_connect(webView, "permission-request", G_CALLBACK(decidePermissionRequest), nullptr);
@@ -318,16 +414,9 @@ int main(int argc, char *argv[])
         webkit_web_view_set_background_color(webView, &color);
 
     if (uriArguments) {
-        const char* uri = uriArguments[0];
-        if (g_str_equal(uri, "about:gpu"))
-            uri = "webkit://gpu";
-
-        GFile* file = g_file_new_for_commandline_arg(uri);
-        char* url = g_file_get_uri(file);
-        g_object_unref(file);
-        webkit_web_view_load_uri(webView, url);
-        g_free(url);
-    } else if (automationMode)
+        // Playwright: avoid weird url transformation like http://trac.webkit.org/r240840
+        webkit_web_view_load_uri(webView, uriArguments[0]);
+    } else if (automationMode || inspectorPipe)
         webkit_web_view_load_uri(webView, "about:blank");
     else
         webkit_web_view_load_uri(webView, "https://wpewebkit.org");
@@ -337,8 +426,7 @@ int main(int argc, char *argv[])
     g_hash_table_destroy(openViews);
 
 
-    if (privateMode || automationMode)
-        g_object_unref(webContext);
+    g_object_unref(webContext);
     g_main_loop_unref(loop);
 
     return 0;
diff --git a/Tools/PlatformWin.cmake b/Tools/PlatformWin.cmake
index 44301d5fef9c977dc0228b9de1ae75263efd9014..0c8c7e176a6e02ca04872cdd362d0a8927728557 100644
--- a/Tools/PlatformWin.cmake
+++ b/Tools/PlatformWin.cmake
@@ -10,4 +10,5 @@ endif ()
 
 if (ENABLE_WEBKIT)
     add_subdirectory(WebKitTestRunner)
+    add_subdirectory(Playwright/win)
 endif ()
diff --git a/Tools/Scripts/build-webkit b/Tools/Scripts/build-webkit
index 0500097b2d4935909840b278a476000d0287a20c..572d483fcfbee9c71c8aa87e24d9c28cd8939381 100755
--- a/Tools/Scripts/build-webkit
+++ b/Tools/Scripts/build-webkit
@@ -249,7 +249,7 @@ if (isAppleCocoaWebKit()) {
     push @projects, ("Source/WebKit");
 
     if (!isEmbeddedWebKit()) {
-        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 908ee7c691cab06482f6182b65d31c524bb9f23f..c40917d4e66ab86212187b56c4e5108175e11f0e 100644
--- a/Tools/WebKitTestRunner/TestController.cpp
+++ b/Tools/WebKitTestRunner/TestController.cpp
@@ -730,7 +730,8 @@ 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/wpe/backends/HeadlessViewBackend.cpp b/Tools/wpe/backends/HeadlessViewBackend.cpp
index d0af19a9aba9aeab8aa3acb2f8c1129f83e07cd7..b32f3eb1495f5f21f059a9eca236bbbf9584b682 100644
--- a/Tools/wpe/backends/HeadlessViewBackend.cpp
+++ b/Tools/wpe/backends/HeadlessViewBackend.cpp
@@ -148,27 +148,24 @@ void HeadlessViewBackend::updateSnapshot(struct wpe_fdo_shm_exported_buffer* exp
             return;
     }
 
-    uint32_t bufferStride = cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, m_width);
-    uint8_t* buffer = new uint8_t[bufferStride * m_height];
-    memset(buffer, 0, bufferStride * m_height);
+    uint32_t width = std::max(0, wl_shm_buffer_get_width(shmBuffer));
+    uint32_t height = std::max(0, wl_shm_buffer_get_height(shmBuffer));
+    if (!width || !height) {
+        fprintf(stderr, "HeadlessViewBackend::updateSnapshot shmBuffer is empty: %ux%u\n", width, height);
+        return;
+    }
 
+    uint32_t bufferStride = cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, width);
+    uint32_t stride = std::max(0, wl_shm_buffer_get_stride(shmBuffer));
+    if (bufferStride != stride) {
+        fprintf(stderr, "bufferStride != stride: %u != %u\n", bufferStride, stride);
+        return;
+    }
+    uint8_t* buffer = new uint8_t[bufferStride * height];
     {
-        uint32_t width = std::min<uint32_t>(m_width, std::max(0, wl_shm_buffer_get_width(shmBuffer)));
-        uint32_t height = std::min<uint32_t>(m_height, std::max(0, wl_shm_buffer_get_height(shmBuffer)));
-        uint32_t stride = std::max(0, wl_shm_buffer_get_stride(shmBuffer));
-
         wl_shm_buffer_begin_access(shmBuffer);
         auto* data = static_cast<uint8_t*>(wl_shm_buffer_get_data(shmBuffer));
-
-        for (uint32_t y = 0; y < height; ++y) {
-            for (uint32_t x = 0; x < width; ++x) {
-                buffer[bufferStride * y + 4 * x + 0] = data[stride * y + 4 * x + 0];
-                buffer[bufferStride * y + 4 * x + 1] = data[stride * y + 4 * x + 1];
-                buffer[bufferStride * y + 4 * x + 2] = data[stride * y + 4 * x + 2];
-                buffer[bufferStride * y + 4 * x + 3] = data[stride * y + 4 * x + 3];
-            }
-        }
-
+        memcpy(buffer, data, bufferStride * height);
         wl_shm_buffer_end_access(shmBuffer);
     }
 
@@ -176,7 +173,7 @@ void HeadlessViewBackend::updateSnapshot(struct wpe_fdo_shm_exported_buffer* exp
         cairo_surface_destroy(m_snapshot);
 
     m_snapshot = cairo_image_surface_create_for_data(buffer, CAIRO_FORMAT_ARGB32,
-        m_width, m_height, cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, m_width));
+        width, height, cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, width));
 
     static cairo_user_data_key_t bufferKey;
     cairo_surface_set_user_data(m_snapshot, &bufferKey, buffer,