Move Singleton and related structs to namespace base

chrome/browser/chromeos/login/signin/oauth2_login_manager_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 CHROME_BROWSER_CHROMEOS_LOGIN_SIGNIN_OAUTH2_LOGIN_MANAGER_FACTORY_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SIGNIN_OAUTH2_LOGIN_MANAGER_FACTORY_H_
 
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
@@ skipping 10 matching lines @@
     : public BrowserContextKeyedServiceFactory {
  public:
   // Returns the instance of OAuth2LoginManager associated with this
   // |profile| (creates one if none exists).
   static OAuth2LoginManager* GetForProfile(Profile* profile);
 
   // Returns an instance of the OAuth2LoginManagerFactory singleton.
   static OAuth2LoginManagerFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<OAuth2LoginManagerFactory>;
+  friend struct base::DefaultSingletonTraits<OAuth2LoginManagerFactory>;
 
   OAuth2LoginManagerFactory();
   ~OAuth2LoginManagerFactory() override;
 
   // BrowserContextKeyedServiceFactory implementation.
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
 
   DISALLOW_COPY_AND_ASSIGN(OAuth2LoginManagerFactory);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SIGNIN_OAUTH2_LOGIN_MANAGER_FACTORY_H_