cc: Introduce BeginFrame sequence numbers and acknowledgements.

content/browser/renderer_host/render_widget_host_view_base.h

Index: content/browser/renderer_host/render_widget_host_view_base.h
diff --git a/content/browser/renderer_host/render_widget_host_view_base.h b/content/browser/renderer_host/render_widget_host_view_base.h
index 1e9fbb09c725cbb5b3fc92e5e433ad81d2915cc8..34baa43f98a277ab7c4e91625def3d0bc29b1e7e 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.h
+++ b/content/browser/renderer_host/render_widget_host_view_base.h
@@ -19,6 +19,7 @@
 #include "base/strings/string16.h"
 #include "base/timer/timer.h"
 #include "build/build_config.h"
+#include "cc/output/begin_frame_args.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/surfaces/surface_id.h"
 #include "content/browser/renderer_host/event_with_latency_info.h"
@@ -210,6 +211,8 @@ class CONTENT_EXPORT RenderWidgetHostViewBase : public RenderWidgetHostView,
   virtual void OnSwapCompositorFrame(uint32_t compositor_frame_sink_id,
                                      cc::CompositorFrame frame) {}
 
+  virtual void OnBeginFrameDidNotDraw(const cc::BeginFrameAck& ack) {}
+
   // This method exists to allow removing of displayed graphics, after a new
   // page has been loaded, to prevent the displayed URL from being out of sync
   // with what is visible on screen.