Move Singleton and related structs to namespace base

chrome/browser/extensions/api/proxy/proxy_api.h

 // Copyright (c) 2012 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.
 
 // Defines the Chrome Extensions Proxy Settings API relevant classes to realize
 // the API as specified in the extension API JSON.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_PROXY_PROXY_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_PROXY_PROXY_API_H_
 
@@ skipping 39 matching lines @@
   void OnProxyError(EventRouterForwarder* event_router,
                     void* profile,
                     int error_code);
 
   void OnPACScriptError(EventRouterForwarder* event_router,
                         void* profile,
                         int line_number,
                         const base::string16& error);
 
  private:
-  friend struct DefaultSingletonTraits<ProxyEventRouter>;
+  friend struct base::DefaultSingletonTraits<ProxyEventRouter>;
 
   ProxyEventRouter();
   ~ProxyEventRouter();
 
   DISALLOW_COPY_AND_ASSIGN(ProxyEventRouter);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_PROXY_PROXY_API_H_