Expose locks for CopyFromCompositingSurface/CopyFromBackingStore API

content/browser/renderer_host/renderer_frame_manager.h

 // Copyright 2013 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 CONTENT_BROWSER_RENDERER_HOST_RENDERER_FRAME_MANAGER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDERER_FRAME_MANAGER_H_
 
 #include <list>
 #include <map>
 
@@ skipping 10 matching lines @@
 };
 
 class CONTENT_EXPORT RendererFrameManager {
  public:
   static RendererFrameManager* GetInstance();
 
   void AddFrame(RendererFrameManagerClient*, bool locked);
   void RemoveFrame(RendererFrameManagerClient*);
   void LockFrame(RendererFrameManagerClient*);
   void UnlockFrame(RendererFrameManagerClient*);
+  size_t LockedCount(RendererFrameManagerClient*);
 
   size_t max_number_of_saved_frames() const {
     return max_number_of_saved_frames_;
   }
 
  private:
   RendererFrameManager();
   ~RendererFrameManager();
   void CullUnlockedFrames();
 
   friend struct DefaultSingletonTraits<RendererFrameManager>;
 
-  std::map<RendererFrameManagerClient*, size_t> locked_frames_;
-  std::list<RendererFrameManagerClient*> unlocked_frames_;
+  typedef std::map<RendererFrameManagerClient*, size_t> LockedFrameCount;
+  LockedFrameCount locked_frames_;
+  typedef std::list<RendererFrameManagerClient*> UnlockedFrames;
+  UnlockedFrames unlocked_frames_;
   size_t max_number_of_saved_frames_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererFrameManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDERER_FRAME_MANAGER_H_