exo: Implement presentation interface.

components/exo/compositor_frame_sink_holder.h

Index: components/exo/compositor_frame_sink_holder.h
diff --git a/components/exo/compositor_frame_sink_holder.h b/components/exo/compositor_frame_sink_holder.h
index 59cc9879e8908be5adeeae3adf1a92fa5b83bd4c..f8682a7c3353abb78c6b0bbf2d20717d0690f33b 100644
--- a/components/exo/compositor_frame_sink_holder.h
+++ b/components/exo/compositor_frame_sink_holder.h
@@ -47,10 +47,6 @@ class CompositorFrameSinkHolder
     return weak_factory_.GetWeakPtr();
   }
 
-  using FrameCallback = base::Callback<void(base::TimeTicks frame_time)>;
-  void ActivateFrameCallbacks(std::list<FrameCallback>* frame_callbacks);
-  void CancelFrameCallbacks();
-
   void SetNeedsBeginFrame(bool needs_begin_frame);
 
   void Satisfy(const cc::SurfaceSequence& sequence);
@@ -92,7 +88,6 @@ class CompositorFrameSinkHolder
   Surface* surface_;
   std::unique_ptr<CompositorFrameSink> frame_sink_;
 
-  std::list<FrameCallback> active_frame_callbacks_;
   std::unique_ptr<cc::ExternalBeginFrameSource> begin_frame_source_;
   bool needs_begin_frame_ = false;
   cc::BeginFrameArgs last_begin_frame_args_;