Move Singleton and related structs to namespace base

chrome/browser/content_settings/cookie_settings_factory.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.
 
 #ifndef CHROME_BROWSER_CONTENT_SETTINGS_COOKIE_SETTINGS_FACTORY_H_
 #define CHROME_BROWSER_CONTENT_SETTINGS_COOKIE_SETTINGS_FACTORY_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 12 matching lines @@
  public:
   // Returns the |CookieSettings| associated with the |profile|.
   //
   // This should only be called on the UI thread.
   static scoped_refptr<content_settings::CookieSettings> GetForProfile(
       Profile* profile);
 
   static CookieSettingsFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<CookieSettingsFactory>;
+  friend struct base::DefaultSingletonTraits<CookieSettingsFactory>;
 
   CookieSettingsFactory();
   ~CookieSettingsFactory() override;
 
   // |BrowserContextKeyedBaseFactory| methods:
   void RegisterProfilePrefs(
       user_prefs::PrefRegistrySyncable* registry) override;
   content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override;
   scoped_refptr<RefcountedKeyedService> BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
 
   DISALLOW_COPY_AND_ASSIGN(CookieSettingsFactory);
 };
 
 #endif  // CHROME_BROWSER_CONTENT_SETTINGS_COOKIE_SETTINGS_FACTORY_H_