Move Singleton and related structs to namespace base

chrome/browser/extensions/warning_badge_service_factory.h

 // Copyright 2014 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_EXTENSION_WARNING_BADGE_SERVICE_FACTORY_H_
-#define CHROME_BROWSER_EXTENSIONS_EXTENSION_WARNING_BADGE_SERVICE_FACTORY_H_
+#ifndef CHROME_BROWSER_EXTENSIONS_WARNING_BADGE_SERVICE_FACTORY_H_
+#define CHROME_BROWSER_EXTENSIONS_WARNING_BADGE_SERVICE_FACTORY_H_
 
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
 namespace extensions {
 
 class WarningBadgeService;
 
 class WarningBadgeServiceFactory : public BrowserContextKeyedServiceFactory {
  public:
   static WarningBadgeService* GetForBrowserContext(
       content::BrowserContext* context);
   static WarningBadgeServiceFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<WarningBadgeServiceFactory>;
+  friend struct base::DefaultSingletonTraits<WarningBadgeServiceFactory>;
 
   WarningBadgeServiceFactory();
   ~WarningBadgeServiceFactory() override;
 
   // BrowserContextKeyedServiceFactory implementation
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
   content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override;
   bool ServiceIsCreatedWithBrowserContext() const override;
 
   DISALLOW_COPY_AND_ASSIGN(WarningBadgeServiceFactory);
 };
 
 }  // namespace extensions
 
-#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_WARNING_BADGE_SERVICE_FACTORY_H_
+#endif  // CHROME_BROWSER_EXTENSIONS_WARNING_BADGE_SERVICE_FACTORY_H_