Move Singleton and related structs to namespace base

chrome/browser/services/gcm/instance_id/instance_id_profile_service_factory.h

 // Copyright (c) 2015 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_SERVICES_GCM_INSTANCE_ID_INSTANCE_ID_PROFILE_SERVICE_FACTORY_H_
 #define CHROME_BROWSER_SERVICES_GCM_INSTANCE_ID_INSTANCE_ID_PROFILE_SERVICE_FACTORY_H_
 
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
 namespace instance_id {
 
 class InstanceIDProfileService;
 
 // Singleton that owns all InstanceIDProfileService and associates them with
 // profiles.
 class InstanceIDProfileServiceFactory :
     public BrowserContextKeyedServiceFactory {
  public:
   static InstanceIDProfileService* GetForProfile(
       content::BrowserContext* profile);
   static InstanceIDProfileServiceFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<InstanceIDProfileServiceFactory>;
+  friend struct base::DefaultSingletonTraits<InstanceIDProfileServiceFactory>;
 
   InstanceIDProfileServiceFactory();
   ~InstanceIDProfileServiceFactory() override;
 
   // BrowserContextKeyedServiceFactory:
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* profile) const override;
   content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceIDProfileServiceFactory);
 };
 
 }  // namespace instance_id
 
 #endif  // CHROME_BROWSER_SERVICES_GCM_INSTANCE_ID_INSTANCE_ID_PROFILE_SERVICE_FACTORY_H_