Moved the AppNotification system into extensions namespace

chrome/browser/extensions/app_notification_storage.h

 // Copyright (c) 2011 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_APP_NOTIFICATION_STORAGE_H__
 #define CHROME_BROWSER_EXTENSIONS_APP_NOTIFICATION_STORAGE_H__
 
 #include <set>
 
 #include "chrome/browser/extensions/app_notification.h"
 
 class FilePath;
 
+namespace extensions {
+
 // Represents storage for app notifications for a particular extension id.
 //
 // IMPORTANT NOTE: Instances of this class should only be used on the FILE
 // thread.
 class AppNotificationStorage {
  public:
   // Must be called on the FILE thread. The storage will be created at |path|.
   static AppNotificationStorage* Create(const FilePath& path);
 
   virtual ~AppNotificationStorage();
 
   // Get the set of extension id's that have entries, putting them into
   // |result|.
   virtual bool GetExtensionIds(std::set<std::string>* result) = 0;
 
   // Gets the list of stored notifications for extension_id. On success, writes
   // results into |result|. On error, returns false.
   virtual bool Get(const std::string& extension_id,
                    AppNotificationList* result) = 0;
 
   // Writes the |list| for |extension_id| into storage.
   virtual bool Set(const std::string& extension_id,
                    const AppNotificationList& list) = 0;
 
   // Deletes all data for |extension_id|.
   virtual bool Delete(const std::string& extension_id) = 0;
 };
 
+}  // namespace extensions
+
 #endif  // CHROME_BROWSER_EXTENSIONS_APP_NOTIFICATION_STORAGE_H__