Move Singleton and related structs to namespace base

chrome/browser/chromeos/extensions/file_manager/event_router_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_CHROMEOS_EXTENSIONS_FILE_MANAGER_EVENT_ROUTER_FACTORY_H_
 #define CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_EVENT_ROUTER_FACTORY_H_
 
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
@@ skipping 13 matching lines @@
   static EventRouterFactory* GetInstance();
 
  protected:
   // BrowserContextKeyedBaseFactory overrides:
   content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override;
   bool ServiceIsCreatedWithBrowserContext() const override;
   bool ServiceIsNULLWhileTesting() const override;
 
  private:
-  friend struct DefaultSingletonTraits<EventRouterFactory>;
+  friend struct base::DefaultSingletonTraits<EventRouterFactory>;
 
   EventRouterFactory();
   ~EventRouterFactory() override;
 
   // BrowserContextKeyedServiceFactory:
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
 };
 
 }  // namespace file_manager
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_EVENT_ROUTER_FACTORY_H_