Add BeginFrameObserverProxy

content/browser/compositor/delegated_frame_host.h

Index: content/browser/compositor/delegated_frame_host.h
diff --git a/content/browser/compositor/delegated_frame_host.h b/content/browser/compositor/delegated_frame_host.h
index a3b43855b503ebd63b804d4971e6ec1b8085ed4b..587aa1dbc7e31106e9564f48c3be0c0c6e16e8ee 100644
--- a/content/browser/compositor/delegated_frame_host.h
+++ b/content/browser/compositor/delegated_frame_host.h
@@ -26,6 +26,7 @@
 namespace cc {
 class SurfaceFactory;
 enum class SurfaceDrawStatus;
+struct BeginFrameArgs;
 }
 
 namespace media {
@@ -65,6 +66,8 @@ class CONTENT_EXPORT DelegatedFrameHostClient {
   virtual void DelegatedFrameHostUpdateVSyncParameters(
       const base::TimeTicks& timebase,
       const base::TimeDelta& interval) = 0;
+  virtual void DelegatedFrameHostSendBeginFrame(
+      const cc::BeginFrameArgs& args) = 0;
 };
 
 // The DelegatedFrameHost is used to host all of the RenderWidgetHostView state
@@ -73,6 +76,7 @@ class CONTENT_EXPORT DelegatedFrameHostClient {
 // the ui::Compositor associated with its DelegatedFrameHostClient.
 class CONTENT_EXPORT DelegatedFrameHost
     : public ui::CompositorObserver,
+      public ui::CompositorBeginFrameObserver,
       public ui::CompositorVSyncManager::Observer,
       public ui::LayerOwnerDelegate,
       public ImageTransportFactoryObserver,
@@ -81,7 +85,8 @@ class CONTENT_EXPORT DelegatedFrameHost
       public cc::SurfaceFactoryClient,
       public base::SupportsWeakPtr<DelegatedFrameHost> {
  public:
-  DelegatedFrameHost(DelegatedFrameHostClient* client);
+  DelegatedFrameHost(DelegatedFrameHostClient* client,
+                     bool begin_frame_scheduling_enabled);
   ~DelegatedFrameHost() override;
 
   bool CanCopyToBitmap() const;
@@ -113,6 +118,7 @@ class CONTENT_EXPORT DelegatedFrameHost
       scoped_ptr<RenderWidgetHostViewFrameSubscriber> subscriber);
   void EndFrameSubscription();
   bool HasFrameSubscriber() const { return frame_subscriber_; }
+  void OnSetNeedsBeginFrames(bool needs_begin_frames);
 
   // Exposed for tests.
   cc::DelegatedFrameProvider* FrameProviderForTesting() const {
@@ -149,6 +155,9 @@ class CONTENT_EXPORT DelegatedFrameHost
   void UnlockResources();
   void RequestCopyOfOutput(scoped_ptr<cc::CopyOutputRequest> request);
 
+  void StartObservingBeginFrames();
+  void StopObservingBeginFrames();
+
   // Overridden from ui::CompositorObserver:
   void OnCompositingDidCommit(ui::Compositor* compositor) override;
   void OnCompositingStarted(ui::Compositor* compositor,
@@ -162,6 +171,9 @@ class CONTENT_EXPORT DelegatedFrameHost
   void OnUpdateVSyncParameters(base::TimeTicks timebase,
                                base::TimeDelta interval) override;
 
+  // Overridden from ui::CompositorBeginFrameObserver:
+  void OnSendBeginFrame(const cc::BeginFrameArgs& args) override;
+
   // Overridden from ui::LayerOwnerObserver:
   void OnLayerRecreated(ui::Layer* old_layer, ui::Layer* new_layer) override;
 
@@ -245,11 +257,11 @@ class CONTENT_EXPORT DelegatedFrameHost
   // layer.
   bool use_surfaces_;
 
-  std::vector<base::Closure> on_compositing_did_commit_callbacks_;

[danakj, 2015/03/13 20:04:40]

unrelated move?

[simonhong, 2015/03/17 16:11:34]

Done.

-
   // The vsync manager we are observing for changes, if any.
   scoped_refptr<ui::CompositorVSyncManager> vsync_manager_;
 
+  std::vector<base::Closure> on_compositing_did_commit_callbacks_;
+
   // The current VSync timebase and interval. These are zero until the first
   // call to OnUpdateVSyncParameters().
   base::TimeTicks vsync_timebase_;
@@ -337,6 +349,17 @@ class CONTENT_EXPORT DelegatedFrameHost
       yuv_readback_pipeline_;
 
   scoped_ptr<DelegatedFrameEvictor> delegated_frame_evictor_;
+
+  // True when unified BeginFrame scheduing is used.

[no sievers, 2015/03/13 20:30:54]

nit: typo "scheduling'

What's 'unified'?

[brianderson, 2015/03/13 20:53:52]

It's the concept of using a common code path for platforms to send the
BeginFrame message. Probably don't need to use the word "unified" in the code.

How about:

// True when BeginFrame messages are used.

[simonhong, 2015/03/17 16:11:34]

Done.

+  bool begin_frame_scheduling_enabled_;
+
+  // True when RenderWidget needs a BeginFrame.

[no sievers, 2015/03/13 20:30:54]

nit: you mean 'need BeginFrame messages' like var name and other function names?

[simonhong, 2015/03/17 16:11:34]

Done.

+  bool needs_begin_frames_;
+
+  // Pass |last_sent_begin_frame_args_| to compositor when |this| is added as a
+  // CompositorBeginFrameObserver. With this, Compositor can determine whether
+  // latest BeginFrameArgs can be used immediately or not.
+  cc::BeginFrameArgs last_sent_begin_frame_args_;
 };
 
 }  // namespace content