cc: Introduce BeginFrame sequence numbers and acknowledgements.

content/browser/frame_host/render_widget_host_view_child_frame.h

Index: content/browser/frame_host/render_widget_host_view_child_frame.h
diff --git a/content/browser/frame_host/render_widget_host_view_child_frame.h b/content/browser/frame_host/render_widget_host_view_child_frame.h
index 9af289d782d4706a25a8ac21a7fbc264875fc34d..2dac9ed87a2cff9f29c63884d286446e9f74aaba 100644
--- a/content/browser/frame_host/render_widget_host_view_child_frame.h
+++ b/content/browser/frame_host/render_widget_host_view_child_frame.h
@@ -15,6 +15,7 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "build/build_config.h"
+#include "cc/output/begin_frame_args.h"
 #include "cc/resources/returned_resource.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/surfaces/surface_factory_client.h"
@@ -114,6 +115,7 @@ class CONTENT_EXPORT RenderWidgetHostViewChildFrame
                        InputEventAckState ack_result) override;
   void OnSwapCompositorFrame(uint32_t compositor_frame_sink_id,
                              cc::CompositorFrame frame) override;
+  void OnBeginFrameDidNotDraw(cc::BeginFrameAck ack) override;
   // Since the URL of content rendered by this class is not displayed in
   // the URL bar, this method does not need an implementation.
   void ClearCompositorFrame() override {}
@@ -206,6 +208,9 @@ class CONTENT_EXPORT RenderWidgetHostViewChildFrame
   void ClearCompositorSurfaceIfNecessary();
 
   void ProcessFrameSwappedCallbacks();
+  void DidSwapFrame(uint64_t source_id,
+                    uint64_t sequence_number,
+                    uint64_t oldest_incorporated_frame);
 
   // The last scroll offset of the view.
   gfx::Vector2dF last_scroll_offset_;