Bug 1607984 - P9. Implement nsIThreadRetargetableStreamListener in ParentChannelListerner. r=valentin

The DocumentLoadListener is setting up a ParentChannelListener to go in between the normal listener->channel chain.
ParentChannelListener not implementing nsIThreadRetargetableStreamListener would prevent a nsHtml5StreamParser settings things up so that OnDataAvailable could be sent to a html parser thread off the main thread; improving performance.

Differential Revision: https://phabricator.services.mozilla.com/D70006

netwerk/protocol/http/ParentChannelListener.cpp

@@ -70,6 +70,7 @@ NS_INTERFACE_MAP_BEGIN(ParentChannelListener)
   NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
   NS_INTERFACE_MAP_ENTRY(nsIMultiPartChannelListener)
   NS_INTERFACE_MAP_ENTRY(nsINetworkInterceptController)
+  NS_INTERFACE_MAP_ENTRY(nsIThreadRetargetableStreamListener)
   NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAuthPromptProvider, mBrowsingContext)
   NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIRemoteWindowContext, mBrowsingContext)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIInterfaceRequestor)
@@ -446,5 +447,22 @@ ParentChannelListener::GetUsePrivateBrowsing(bool* aUsePrivateBrowsing) {
   return NS_OK;
 }
 
+//-----------------------------------------------------------------------------
+// ParentChannelListener::nsIThreadRetargetableStreamListener
+//
+
+NS_IMETHODIMP
+ParentChannelListener::CheckListenerChain() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsCOMPtr<nsIThreadRetargetableStreamListener> listener =
+      do_QueryInterface(mNextListener);
+  if (!listener) {
+    return NS_ERROR_NO_INTERFACE;
+  }
+
+  return listener->CheckListenerChain();
+}
+
 }  // namespace net
 }  // namespace mozilla

netwerk/protocol/http/ParentChannelListener.h

@@ -8,14 +8,14 @@
 #ifndef mozilla_net_ParentChannelListener_h
 #define mozilla_net_ParentChannelListener_h
 
+#include "mozilla/dom/CanonicalBrowsingContext.h"
 #include "nsIAuthPromptProvider.h"
 #include "nsIInterfaceRequestor.h"
-#include "nsINetworkInterceptController.h"
-#include "nsIStreamListener.h"
 #include "nsIMultiPartChannel.h"
+#include "nsINetworkInterceptController.h"
 #include "nsIRemoteWindowContext.h"
-#include "mozilla/dom/CanonicalBrowsingContext.h"
+#include "nsIStreamListener.h"
-#include "mozilla/dom/CanonicalBrowsingContext.h"
+#include "nsIThreadRetargetableStreamListener.h"
 
 namespace mozilla {
 namespace net {
@@ -35,6 +35,7 @@ class ParentChannelListener final : public nsIInterfaceRequestor,
                                     public nsIStreamListener,
                                     public nsIMultiPartChannelListener,
                                     public nsINetworkInterceptController,
+                                    public nsIThreadRetargetableStreamListener,
                                     private nsIAuthPromptProvider,
                                     private nsIRemoteWindowContext {
  public:
@@ -46,6 +47,7 @@ class ParentChannelListener final : public nsIInterfaceRequestor,
   NS_DECL_NSINETWORKINTERCEPTCONTROLLER
   NS_DECL_NSIAUTHPROMPTPROVIDER
   NS_DECL_NSIREMOTEWINDOWCONTEXT
+  NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
 
   NS_DECLARE_STATIC_IID_ACCESSOR(PARENT_CHANNEL_LISTENER)