Refactoring the way begin frame sources inside scheduler work.

cc/trees/layer_tree_host_impl.h

Index: cc/trees/layer_tree_host_impl.h
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index 45fefe578b6f482c8adfa4288d0d5389c915c77a..e8c46ef5f06c7a4d2ce41d324e20993f43da96ae 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -32,6 +32,7 @@
 #include "cc/resources/resource_provider.h"
 #include "cc/resources/tile_manager.h"
 #include "cc/scheduler/draw_result.h"
+#include "cc/scheduler/frame_source.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/rect.h"
@@ -70,7 +71,6 @@ class LayerTreeHostImplClient {
   virtual void SetMaxSwapsPendingOnImplThread(int max) = 0;
   virtual void DidSwapBuffersOnImplThread() = 0;
   virtual void DidSwapBuffersCompleteOnImplThread() = 0;
-  virtual void BeginFrame(const BeginFrameArgs& args) = 0;
   virtual void OnCanDrawStateChanged(bool can_draw) = 0;
   virtual void NotifyReadyToActivate() = 0;
   // Please call these 3 functions through
@@ -110,6 +110,7 @@ class CC_EXPORT LayerTreeHostImpl
       public OutputSurfaceClient,
       public TopControlsManagerClient,
       public ScrollbarAnimationControllerClient,
+      public BaseBeginFrameSource,

[brianderson, 2014/06/17 06:24:43]

How difficult would it be to make OutputSurface inherit from BeginFrameSource
instead? We'd have to set the sink every time a new OutputSurface is created.

       public base::SupportsWeakPtr<LayerTreeHostImpl> {
  public:
   static scoped_ptr<LayerTreeHostImpl> Create(
@@ -259,6 +260,10 @@ class CC_EXPORT LayerTreeHostImpl
   virtual void SetTreeActivationCallback(const base::Closure& callback)
       OVERRIDE;
 
+  // BeginFrameSource implementation.
+  virtual void OnGenerateChange(bool generate_frames) OVERRIDE;
+  virtual std::string TypeString() const OVERRIDE;
+
   // Called from LayerTreeImpl.
   void OnCanDrawStateChangedForTree();
 
@@ -284,7 +289,6 @@ class CC_EXPORT LayerTreeHostImpl
   const RendererCapabilitiesImpl& GetRendererCapabilities() const;
 
   virtual bool SwapBuffers(const FrameData& frame);
-  void SetNeedsBeginFrame(bool enable);
   virtual void WillBeginImplFrame(const BeginFrameArgs& args);
   void DidModifyTilePriorities();