This change introduces NetworkRequest object that encapsulates
internal redirects as they happen in netwerk/ stack.
NetworkRequest now serves as both ResponseBodyListener and NotificationCallbacks.
When httpChannel is intercepted by Service Worker:
- it gets an internal redirect to another channel with the same id;
- once serivce worker responds, the channel gets the data, but
does not get any onResponse notifications.
So, we update our ResponseBodyListener (the nsIRequestObserver implementation)
to the new request and force onResponse from there once data is available or
request finishes.
