Move Singleton and related structs to namespace base

ios/chrome/browser/translate/translate_accept_languages_factory.h

 // Copyright 2014 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 IOS_CHROME_BROWSER_TRANSLATE_TRANSLATE_ACCEPT_LANGUAGES_FACTORY_H_
 #define IOS_CHROME_BROWSER_TRANSLATE_TRANSLATE_ACCEPT_LANGUAGES_FACTORY_H_
 
 #include "base/basictypes.h"
 #include "base/memory/singleton.h"
 #include "components/keyed_service/ios/browser_state_keyed_service_factory.h"
 
 namespace translate {
 class TranslateAcceptLanguages;
 }
 
 namespace ios {
 class ChromeBrowserState;
 }
 
 // TranslateAcceptLanguagesFactory is a way to associate a
 // TranslateAcceptLanguages instance to a BrowserState.
 class TranslateAcceptLanguagesFactory : public BrowserStateKeyedServiceFactory {
  public:
   static translate::TranslateAcceptLanguages* GetForBrowserState(
       ios::ChromeBrowserState* browser_state);
   static TranslateAcceptLanguagesFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<TranslateAcceptLanguagesFactory>;
+  friend struct base::DefaultSingletonTraits<TranslateAcceptLanguagesFactory>;
 
   TranslateAcceptLanguagesFactory();
   ~TranslateAcceptLanguagesFactory() override;
 
   // BrowserStateKeyedServiceFactory implementation.
   scoped_ptr<KeyedService> BuildServiceInstanceFor(
       web::BrowserState* context) const override;
   web::BrowserState* GetBrowserStateToUse(
       web::BrowserState* context) const override;
 
   DISALLOW_COPY_AND_ASSIGN(TranslateAcceptLanguagesFactory);
 };
 
 #endif  // IOS_CHROME_BROWSER_TRANSLATE_TRANSLATE_ACCEPT_LANGUAGES_FACTORY_H_