Expose locks for CopyFromCompositingSurface/CopyFromBackingStore API

content/browser/renderer_host/delegated_frame_evictor.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_DELEGATED_FRAME_EVICTOR_H_
 #define CONTENT_BROWSER_RENDERER_HOST_DELEGATED_FRAME_EVICTOR_H_
 
 #include "content/browser/renderer_host/renderer_frame_manager.h"
 #include "content/common/content_export.h"
 
 namespace content {
 
 class CONTENT_EXPORT DelegatedFrameEvictorClient {
  public:
   virtual ~DelegatedFrameEvictorClient() {}
   virtual void EvictDelegatedFrame() = 0;
 };
 
 class CONTENT_EXPORT DelegatedFrameEvictor : public RendererFrameManagerClient {
  public:
   // |client| must outlive |this|.
   explicit DelegatedFrameEvictor(DelegatedFrameEvictorClient* client);
   virtual ~DelegatedFrameEvictor();
 
   void SwappedFrame(bool visible);
   void DiscardedFrame();
   void SetVisible(bool visible);
   void LockFrame();
   void UnlockFrame();
+  bool HasFrame() { return has_frame_; }
 
  private:
   // RendererFrameManagerClient implementation.
   virtual void EvictCurrentFrame() OVERRIDE;
 
   DelegatedFrameEvictorClient* client_;
   bool has_frame_;
 
   DISALLOW_COPY_AND_ASSIGN(DelegatedFrameEvictor);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_DELEGATED_FRAME_EVICTOR_H_