Move Singleton and related structs to namespace base

chrome/browser/extensions/extension_management.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_MANAGEMENT_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_MANAGEMENT_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 180 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(ExtensionManagement);
 };
 
 class ExtensionManagementFactory : public BrowserContextKeyedServiceFactory {
  public:
   static ExtensionManagement* GetForBrowserContext(
       content::BrowserContext* context);
   static ExtensionManagementFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<ExtensionManagementFactory>;
+  friend struct base::DefaultSingletonTraits<ExtensionManagementFactory>;
 
   ExtensionManagementFactory();
   ~ExtensionManagementFactory() override;
 
   // BrowserContextKeyedServiceExtensionManagementFactory:
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
   content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override;
   void RegisterProfilePrefs(
       user_prefs::PrefRegistrySyncable* registry) override;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionManagementFactory);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_MANAGEMENT_H_