Move Singleton and related structs to namespace base

chrome/browser/extensions/api/dial/dial_api_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_EXTENSIONS_API_DIAL_DIAL_API_FACTORY_H_
 #define CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_API_FACTORY_H_
 
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/refcounted_browser_context_keyed_service_factory.h"
 
 namespace extensions {
 
 class DialAPI;
 
 class DialAPIFactory : public RefcountedBrowserContextKeyedServiceFactory {
  public:
   static scoped_refptr<DialAPI> GetForBrowserContext(
       content::BrowserContext* context);
 
   static DialAPIFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<DialAPIFactory>;
+  friend struct base::DefaultSingletonTraits<DialAPIFactory>;
 
   DialAPIFactory();
   ~DialAPIFactory() override;
 
   // BrowserContextKeyedServiceFactory:
   scoped_refptr<RefcountedKeyedService> BuildServiceInstanceFor(
       content::BrowserContext* profile) const override;
   bool ServiceIsCreatedWithBrowserContext() const override;
   bool ServiceIsNULLWhileTesting() const override;
 
   DISALLOW_COPY_AND_ASSIGN(DialAPIFactory);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_API_FACTORY_H_