Move ExtensionSystem into extensions namespace

chrome/browser/extensions/extension_system_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_EXTENSION_SYSTEM_FACTORY_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_FACTORY_H_
 #pragma once
 
 #include "base/memory/singleton.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile_keyed_service_factory.h"
 
-class ExtensionSystem;
 class Profile;
 class ProfileKeyedService;
 
+namespace extensions {
+class ExtensionSystem;
+
 // ProfileKeyedServiceFactory for ExtensionSystemImpl::Shared.
 // Should not be used except by ExtensionSystem(Factory).
 class ExtensionSystemSharedFactory : public ProfileKeyedServiceFactory {
  public:
-  static ExtensionSystemImpl::Shared* GetForProfile(Profile* profile);
+  static ExtensionSystemImpl::Shared* GetForProfile(
+      Profile* profile);
 
   static ExtensionSystemSharedFactory* GetInstance();
 
  private:
   friend struct DefaultSingletonTraits<ExtensionSystemSharedFactory>;
 
   ExtensionSystemSharedFactory();
   virtual ~ExtensionSystemSharedFactory();
 
   virtual ProfileKeyedService* BuildServiceInstanceFor(
@@ skipping 14 matching lines @@
 
   ExtensionSystemFactory();
   virtual ~ExtensionSystemFactory();
 
   virtual ProfileKeyedService* BuildServiceInstanceFor(
       Profile* profile) const OVERRIDE;
   virtual bool ServiceHasOwnInstanceInIncognito() OVERRIDE;
   virtual bool ServiceIsCreatedWithProfile() OVERRIDE;
 };
 
+}  // namespace extensions
+
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_FACTORY_H_