cc: Plumbing for BeginFrameSource based on Surfaces

cc/surfaces/surface.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 CC_SURFACES_SURFACE_H_
 #define CC_SURFACES_SURFACE_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 62 matching lines @@
     return destruction_dependencies_.size();
   }
 
   const std::vector<SurfaceId>& referenced_surfaces() const {
     return referenced_surfaces_;
   }
 
   bool destroyed() const { return destroyed_; }
   void set_destroyed(bool destroyed) { destroyed_ = destroyed; }
 
+  void AddBeginFrameSource(BeginFrameSource* begin_frame_source);
+  void RemoveBeginFrameSource(BeginFrameSource* begin_frame_source);
+
  private:
   void ClearCopyRequests();
+  void UpdatePrimaryBeginFrameSource();
 
   SurfaceId surface_id_;
   base::WeakPtr<SurfaceFactory> factory_;
   // TODO(jamesr): Support multiple frames in flight.
   scoped_ptr<CompositorFrame> current_frame_;
   int frame_index_;
   bool destroyed_;
   std::vector<SurfaceSequence> destruction_dependencies_;
 
+  // This surface may have multiple BeginFrameSources if it is
+  // on multiple Displays.
+  std::vector<BeginFrameSource*> begin_frame_sources_;
+
   std::vector<SurfaceId> referenced_surfaces_;
 
   DrawCallback draw_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(Surface);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_SURFACE_H_