Simplify mailbox handling for browser plugin

content/renderer/browser_plugin/browser_plugin_compositing_helper.h

 // Copyright (c) 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_RENDERER_BROWSER_PLUGIN_BROWSER_PLUGIN_COMPOSITING_HELPER_H_
 #define  CONTENT_RENDERER_BROWSER_PLUGIN_BROWSER_PLUGIN_COMPOSITING_HELPER_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 38 matching lines @@
                                 int host_id);
   void UpdateVisibility(bool);
  protected:
   // Friend RefCounted so that the dtor can be non-public.
   friend class base::RefCounted<BrowserPluginCompositingHelper>;
  private:
   ~BrowserPluginCompositingHelper();
   void CheckSizeAndAdjustLayerBounds(const gfx::Size& new_size,
                                      float device_scale_factor,
                                      cc::Layer* layer);
-  void FreeMailboxMemory(const std::string& mailbox_name,
-                         unsigned sync_point);
   void MailboxReleased(const std::string& mailbox_name,
                        int gpu_route_id,
                        int gpu_host_id,
                        unsigned sync_point,
                        bool lost_resource);
   int instance_id_;
   int host_routing_id_;
   int last_route_id_;
   int last_host_id_;
   bool last_mailbox_valid_;
   bool ack_pending_;
   bool ack_pending_for_crashed_guest_;
 
   gfx::Size buffer_size_;
 
   scoped_refptr<cc::SolidColorLayer> background_layer_;
   scoped_refptr<cc::TextureLayer> texture_layer_;
   scoped_refptr<cc::DelegatedRendererLayer> delegated_layer_;
   scoped_ptr<WebKit::WebLayer> web_layer_;
   WebKit::WebPluginContainer* container_;
 
   scoped_refptr<BrowserPluginManager> browser_plugin_manager_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_BROWSER_PLUGIN_BROWSER_PLUGIN_COMPOSITING_HELPER_H_