cc: Introduce BeginFrame sequence numbers and acknowledgements.

content/browser/renderer_host/browser_compositor_view_mac.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_BROWSER_COMPOSITOR_VIEW_MAC_H_
 #define CONTENT_BROWSER_RENDERER_HOST_BROWSER_COMPOSITOR_VIEW_MAC_H_
 
 #include <memory>
 
 #include "base/macros.h"
+#include "cc/output/begin_frame_args.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "content/browser/renderer_host/delegated_frame_host.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/compositor_observer.h"
 
 namespace ui {
 class AcceleratedWidgetMac;
 class AcceleratedWidgetMacNSView;
 }
 
@@ skipping 34 matching lines @@
 
   // These will not return nullptr until Destroy is called.
   DelegatedFrameHost* GetDelegatedFrameHost();
 
   // This may return nullptr, if this has detached itself from its
   // ui::Compositor.
   ui::AcceleratedWidgetMac* GetAcceleratedWidgetMac();
 
   void SwapCompositorFrame(uint32_t compositor_frame_sink_id,
                            cc::CompositorFrame frame);
+  void OnBeginFrameDidNotDraw(cc::BeginFrameAck ack);
   void SetHasTransparentBackground(bool transparent);
   void SetDisplayColorSpace(const gfx::ColorSpace& color_space);
   void UpdateVSyncParameters(const base::TimeTicks& timebase,
                              const base::TimeDelta& interval);
   void SetNeedsBeginFrames(bool needs_begin_frames);
 
   // This is used to ensure that the ui::Compositor be attached to the
   // DelegatedFrameHost while the RWHImpl is visible.
   // Note: This should be called before the RWHImpl is made visible and after
   // it has been hidden, in order to ensure that thumbnailer notifications to
@@ skipping 97 matching lines @@
   std::unique_ptr<RecyclableCompositorMac> recyclable_compositor_;
 
   std::unique_ptr<DelegatedFrameHost> delegated_frame_host_;
   std::unique_ptr<ui::Layer> root_layer_;
 
   bool has_transparent_background_ = false;
 
   // The begin frame source being observed.  Null if none.
   cc::BeginFrameSource* begin_frame_source_ = nullptr;
   cc::BeginFrameArgs last_begin_frame_args_;
+  uint64_t oldest_incorporated_frame_ = 0;
   bool needs_begin_frames_ = false;
 
   base::WeakPtrFactory<BrowserCompositorMac> weak_factory_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_BROWSER_COMPOSITOR_VIEW_MAC_H_