Send BeginFrames for the renderer using Mojo

content/renderer/gpu/renderer_compositor_frame_sink.cc

Index: content/renderer/gpu/renderer_compositor_frame_sink.cc
diff --git a/content/renderer/gpu/renderer_compositor_frame_sink.cc b/content/renderer/gpu/renderer_compositor_frame_sink.cc
index 9e7dd13124f220c16f1bbf758a90b1a1cea93021..92547a90b705889c5b1a07ac9d0072274613909a 100644
--- a/content/renderer/gpu/renderer_compositor_frame_sink.cc
+++ b/content/renderer/gpu/renderer_compositor_frame_sink.cc
@@ -171,15 +171,6 @@ void RendererCompositorFrameSink::DidNotProduceFrame(
 void RendererCompositorFrameSink::OnMessageReceived(

[piman, 2017/05/26 16:23:00]

Well then, if this is empty, I think we can remove
RendererCompositorFrameSinkProxy and CompositorForwardingMessageFilter
altogether.

[Saman Sami, 2017/05/26 16:27:35]

I thought about that as well. Even though it's not used now, I think I'll need
them very soon. I'll get rid of them if that's not the case.

     const IPC::Message& message) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  IPC_BEGIN_MESSAGE_MAP(RendererCompositorFrameSink, message)
-    IPC_MESSAGE_HANDLER(ViewMsg_BeginFrame, OnBeginFrameIPC)
-  IPC_END_MESSAGE_MAP()
-}
-
-void RendererCompositorFrameSink::OnBeginFrameIPC(
-    const cc::BeginFrameArgs& args) {
-  if (external_begin_frame_source_)
-    external_begin_frame_source_->OnBeginFrame(args);
 }
 
 void RendererCompositorFrameSink::DidReceiveCompositorFrameAck(
@@ -189,8 +180,8 @@ void RendererCompositorFrameSink::DidReceiveCompositorFrameAck(
 }
 
 void RendererCompositorFrameSink::OnBeginFrame(const cc::BeginFrameArgs& args) {
-  // See crbug.com/709689.
-  NOTREACHED() << "BeginFrames are delivered using Chrome IPC.";
+  if (external_begin_frame_source_)
+    external_begin_frame_source_->OnBeginFrame(args);
 }
 
 void RendererCompositorFrameSink::ReclaimResources(