Add IPC messages to transfer compositor protos

content/browser/renderer_host/render_widget_host_delegate.h

Index: content/browser/renderer_host/render_widget_host_delegate.h
diff --git a/content/browser/renderer_host/render_widget_host_delegate.h b/content/browser/renderer_host/render_widget_host_delegate.h
index a96428c7e17c92169b008823d697a51e563ad2f1..3715558366aaa0d7810b55afb6f75934e8cb7055 100644
--- a/content/browser/renderer_host/render_widget_host_delegate.h
+++ b/content/browser/renderer_host/render_widget_host_delegate.h
@@ -163,6 +163,10 @@ class CONTENT_EXPORT RenderWidgetHostDelegate {
   virtual gfx::NativeViewAccessible GetParentNativeViewAccessible();
 #endif
 
+  // Called when the widget has sent a compositor proto.

[no sievers, 2015/11/14 00:13:43]

nit: can you mention it's used in blimp mode?

[David Trainor- moved to gerrit, 2015/11/16 04:33:58]

Done.

+  virtual void HandleCompositorProto(RenderWidgetHostImpl* render_widget_host,
+                                     const std::vector<char>& proto) {}
+
  protected:
   virtual ~RenderWidgetHostDelegate() {}
 };