cc: Introduce BeginFrame sequence numbers and acknowledgements.

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 18b7651a30dff091144898dfef8d02ec4a14b5e1..2c34d8e9c91d3e8313e0890344d501cca45dc002 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -63,6 +63,10 @@ class WebMouseEvent;
 struct WebCompositionUnderline;
 }
 
+namespace cc {
+struct BeginFrameAck;
+}
+
 #if defined(OS_MACOSX)
 namespace device {
 class PowerSaveBlocker;
@@ -624,6 +628,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl : public RenderWidgetHost,
   void OnSetTooltipText(const base::string16& tooltip_text,
                         blink::WebTextDirection text_direction_hint);
   bool OnSwapCompositorFrame(const IPC::Message& message);
+  void OnBeginFrameDidNotDraw(const cc::BeginFrameAck& ack);
   void OnUpdateRect(const ViewHostMsg_UpdateRect_Params& params);
   void OnQueueSyntheticGesture(const SyntheticGesturePacket& gesture_packet);
   void OnSetCursor(const WebCursor& cursor);