Move Singleton and related structs to namespace base

chrome/browser/google/google_url_tracker_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_GOOGLE_GOOGLE_URL_TRACKER_FACTORY_H_
 #define CHROME_BROWSER_GOOGLE_GOOGLE_URL_TRACKER_FACTORY_H_
 
 #include "base/basictypes.h"
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
 class GoogleURLTracker;
 class Profile;
 
 // Singleton that owns all GoogleURLTrackers and associates them with Profiles.
 class GoogleURLTrackerFactory : public BrowserContextKeyedServiceFactory {
  public:
   // Returns the GoogleURLTracker for |profile|.  This may return NULL for a
   // testing profile.
   static GoogleURLTracker* GetForProfile(Profile* profile);
 
   static GoogleURLTrackerFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<GoogleURLTrackerFactory>;
+  friend struct base::DefaultSingletonTraits<GoogleURLTrackerFactory>;
 
   GoogleURLTrackerFactory();
   ~GoogleURLTrackerFactory() override;
 
   // BrowserContextKeyedServiceFactory:
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* profile) const override;
   void RegisterProfilePrefs(
       user_prefs::PrefRegistrySyncable* registry) override;
   content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override;
   bool ServiceIsCreatedWithBrowserContext() const override;
   bool ServiceIsNULLWhileTesting() const override;
 
   DISALLOW_COPY_AND_ASSIGN(GoogleURLTrackerFactory);
 };
 
 #endif  // CHROME_BROWSER_GOOGLE_GOOGLE_URL_TRACKER_FACTORY_H_