cc: Introduce BeginFrame sequence numbers and acknowledgements.

content/browser/renderer_host/render_widget_host_view_mac.h

Index: content/browser/renderer_host/render_widget_host_view_mac.h
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.h b/content/browser/renderer_host/render_widget_host_view_mac.h
index 95fdd69d632ee251948af0ac3191409f2ef63bdd..7b07e5bdf8432f0b7390c7238408bb8b6a5d5ee7 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.h
+++ b/content/browser/renderer_host/render_widget_host_view_mac.h
@@ -22,6 +22,7 @@
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
+#include "cc/output/begin_frame_args.h"
 #include "cc/surfaces/surface_id.h"
 #include "content/browser/renderer_host/browser_compositor_view_mac.h"
 #include "content/browser/renderer_host/input/mouse_wheel_rails_filter_mac.h"
@@ -302,6 +303,7 @@ class CONTENT_EXPORT RenderWidgetHostViewMac
                           const gfx::Rect& node_bounds_in_screen) override;
   void OnSwapCompositorFrame(uint32_t compositor_frame_sink_id,
                              cc::CompositorFrame frame) override;
+  void OnBeginFrameDidNotDraw(cc::BeginFrameAck ack) override;
   void ClearCompositorFrame() override;
   BrowserAccessibilityManager* CreateBrowserAccessibilityManager(
       BrowserAccessibilityDelegate* delegate, bool for_root_frame) override;