cc: Create ProxyBeginFrameSource

cc/trees/thread_proxy.h

Index: cc/trees/thread_proxy.h
diff --git a/cc/trees/thread_proxy.h b/cc/trees/thread_proxy.h
index 0d15b5a67f2408b7a6673649300d6aeb1a72d40e..b7b04c7ff783e4467f8bc72a7ae3d77ff3d88c60 100644
--- a/cc/trees/thread_proxy.h
+++ b/cc/trees/thread_proxy.h
@@ -177,7 +177,6 @@ class CC_EXPORT ThreadProxy : public Proxy,
   void SetDebugState(const LayerTreeDebugState& debug_state) override;
   void AsValueInto(base::debug::TracedValue* value) const override;
   bool MainFrameWillHappenForTesting() override;
-  void SetChildrenNeedBeginFrames(bool children_need_begin_frames) override;
 
   // LayerTreeHostImplClient implementation
   void UpdateRendererCapabilitiesOnImplThread() override;
@@ -226,7 +225,6 @@ class CC_EXPORT ThreadProxy : public Proxy,
   base::TimeDelta BeginMainFrameToCommitDurationEstimate() override;
   base::TimeDelta CommitToActivateDurationEstimate() override;
   void DidBeginImplFrameDeadline() override;
-  void SendBeginFramesToChildren(const BeginFrameArgs& args) override;
 
   // ResourceUpdateControllerClient implementation
   void ReadyToFinalizeTextureUpdates() override;