Move Singleton and related structs to namespace base

ppapi/proxy/proxy_module.h

 // Copyright (c) 2011 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 PPAPI_PROXY_PROXY_MODULE_H_
 #define PPAPI_PROXY_PROXY_MODULE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
 
+namespace base {
 template<typename T> struct DefaultSingletonTraits;
+}
 
 namespace ppapi {
 namespace proxy {
 
 class PPAPI_PROXY_EXPORT ProxyModule {
  public:
   // The global singleton getter.
   static ProxyModule* GetInstance();
 
   // TODO(viettrungluu): Generalize this for use with other plugins if it proves
   // necessary. (Currently, we can't do this easily, since we can't tell from
   // |PpapiPluginMain()| which plugin will be loaded.)
   const std::string& GetFlashCommandLineArgs();
   void SetFlashCommandLineArgs(const std::string& args);
 
  private:
-  friend struct DefaultSingletonTraits<ProxyModule>;
+  friend struct base::DefaultSingletonTraits<ProxyModule>;
 
   std::string flash_command_line_args_;
 
   ProxyModule();
   ~ProxyModule();
 
   DISALLOW_COPY_AND_ASSIGN(ProxyModule);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PROXY_MODULE_H_