Make software compositing work on Mac.

content/browser/renderer_host/frame_memory_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_FRAME_MEMORY_MANAGER_H_
-#define CONTENT_BROWSER_RENDERER_HOST_FRAME_MEMORY_MANAGER_H_
-
-#include <list>
-#include <set>
-
-#include "base/basictypes.h"
-
-template <typename T> struct DefaultSingletonTraits;
-
-namespace content {
-
-class FrameContainer {
- public:
-  virtual void ReleaseCurrentFrame() = 0;
-};
-
-class FrameMemoryManager {
- public:
-  static FrameMemoryManager* GetInstance();
-
-  void AddFrame(FrameContainer*, bool visible);
-  void RemoveFrame(FrameContainer*);
-  void SetFrameVisibility(FrameContainer*, bool visible);
-
- private:
-  FrameMemoryManager();
-  ~FrameMemoryManager();
-  void CullHiddenFrames();
-  friend struct DefaultSingletonTraits<FrameMemoryManager>;
-
-  std::set<FrameContainer*> visible_frames_;
-  std::list<FrameContainer*> hidden_frames_;
-
-  DISALLOW_COPY_AND_ASSIGN(FrameMemoryManager);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_RENDERER_HOST_FRAME_MEMORY_MANAGER_H_