Move Singleton and related structs to namespace base

chrome/browser/profile_resetter/automatic_profile_resetter_factory.h

 // Copyright 2013 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_PROFILE_RESETTER_AUTOMATIC_PROFILE_RESETTER_FACTORY_H_
 #define CHROME_BROWSER_PROFILE_RESETTER_AUTOMATIC_PROFILE_RESETTER_FACTORY_H_
 
 #include "base/basictypes.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
+namespace base {
 template <typename T>
 struct DefaultSingletonTraits;
+}  // namespace base
 
 class PrefRegistrySimple;
 
 namespace content {
 class BrowserContext;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 class AutomaticProfileResetter;
 
 class AutomaticProfileResetterFactory
     : public BrowserContextKeyedServiceFactory {
  public:
   static AutomaticProfileResetter* GetForBrowserContext(
       content::BrowserContext* context);
   static AutomaticProfileResetterFactory* GetInstance();
 
   // Registers Local State preferences.
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
  private:
-  friend struct DefaultSingletonTraits<AutomaticProfileResetterFactory>;
+  friend struct base::DefaultSingletonTraits<AutomaticProfileResetterFactory>;
 
   AutomaticProfileResetterFactory();
   ~AutomaticProfileResetterFactory() override;
 
   // BrowserContextKeyedServiceFactory:
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
 
   // BrowserContextKeyedBaseFactory:
   void RegisterProfilePrefs(
       user_prefs::PrefRegistrySyncable* registry) override;
   bool ServiceIsCreatedWithBrowserContext() const override;
   bool ServiceIsNULLWhileTesting() const override;
 
   DISALLOW_COPY_AND_ASSIGN(AutomaticProfileResetterFactory);
 };
 
 #endif  // CHROME_BROWSER_PROFILE_RESETTER_AUTOMATIC_PROFILE_RESETTER_FACTORY_H_