Add IPC messages to transfer compositor protos

content/browser/renderer_host/render_widget_host_impl.h

Index: content/browser/renderer_host/render_widget_host_impl.h
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index b40c33fe8759dfaf7b4e832b7d373d0e2606ef78..0837e353f40deb0b09fe30546a291ceaeaf056a7 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -159,6 +159,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl : public RenderWidgetHost,
   void RemoveMouseEventCallback(const MouseEventCallback& callback) override;
   void GetWebScreenInfo(blink::WebScreenInfo* result) override;
   bool GetScreenColorProfile(std::vector<char>* color_profile) override;
+  void HandleCompositorProto(const std::vector<uint8_t>& proto) override;
 
   // Notification that the screen info has changed.
   void NotifyScreenInfoChanged();
@@ -589,6 +590,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl : public RenderWidgetHost,
                           const gfx::Range& range);
   void OnSelectionBoundsChanged(
       const ViewHostMsg_SelectionBounds_Params& params);
+  void OnForwardCompositorProto(const std::vector<uint8_t>& proto);
 
   // Called (either immediately or asynchronously) after we're done with our
   // BackingStore and can send an ACK to the renderer so it can paint onto it