Move Singleton and related structs to namespace base

chrome/browser/extensions/extension_renderer_state.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 CHROME_BROWSER_EXTENSIONS_EXTENSION_RENDERER_STATE_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_RENDERER_STATE_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 19 matching lines @@
 
   // Looks up the tab and window ID for a given request. Returns true if we have
   // the IDs in our map. Called on the IO thread.
   bool GetTabAndWindowId(
       const content::ResourceRequestInfo* info, int* tab_id, int* window_id);
 
  private:
   class RenderViewHostObserver;
   class TabObserver;
   friend class TabObserver;
-  friend struct DefaultSingletonTraits<ExtensionRendererState>;
+  friend struct base::DefaultSingletonTraits<ExtensionRendererState>;
 
   typedef std::pair<int, int> RenderId;
   typedef std::pair<int, int> TabAndWindowId;
   typedef std::map<RenderId, TabAndWindowId> TabAndWindowIdMap;
 
   ExtensionRendererState();
   ~ExtensionRendererState();
 
   // Adds or removes a render view from our map.
   void SetTabAndWindowId(
       int render_process_host_id, int routing_id, int tab_id, int window_id);
   void ClearTabAndWindowId(
       int render_process_host_id, int routing_id);
 
   TabObserver* observer_;
   TabAndWindowIdMap map_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionRendererState);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_RENDERER_STATE_H_