cc: Make separate interface for BeginFrame ipc from OutputSurface

content/renderer/render_thread_impl.h

Index: content/renderer/render_thread_impl.h
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index cb27dff813be817fc5007540c5fa757e2ba00f65..84d2af2140841a8884863612a2f2108514b47e04 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -208,6 +208,10 @@ class CONTENT_EXPORT RenderThreadImpl : public RenderThread,
     return compositor_output_surface_filter_.get();
   }
 
+  IPC::ForwardingMessageFilter* begin_frame_source_filter() const {
+    return begin_frame_source_filter_.get();
+  }
+
   InputHandlerManager* input_handler_manager() const {
     return input_handler_manager_.get();
   }
@@ -540,6 +544,7 @@ class CONTENT_EXPORT RenderThreadImpl : public RenderThread,
   scoped_refptr<InputEventFilter> input_event_filter_;
   scoped_ptr<InputHandlerManager> input_handler_manager_;
   scoped_refptr<IPC::ForwardingMessageFilter> compositor_output_surface_filter_;
+  scoped_refptr<IPC::ForwardingMessageFilter> begin_frame_source_filter_;
 
   scoped_refptr<webkit::gpu::ContextProviderWebContext>
       shared_main_thread_contexts_;