Allow partial update for notification update API

chrome/browser/notifications/notification_ui_manager_impl.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_NOTIFICATIONS_NOTIFICATION_UI_MANAGER_IMPL_H_
 #define CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_UI_MANAGER_IMPL_H_
 
 #include <deque>
 #include <string>
 #include <vector>
@@ skipping 16 matching lines @@
 class NotificationUIManagerImpl
     : public NotificationUIManager,
       public content::NotificationObserver {
  public:
   NotificationUIManagerImpl();
   virtual ~NotificationUIManagerImpl();
 
   // NotificationUIManager:
   virtual void Add(const Notification& notification,
                    Profile* profile) OVERRIDE;
-  virtual bool DoesIdExist(const std::string& notification_id) OVERRIDE;
+  virtual const Notification* FindById(
+      const std::string& notification_id) const OVERRIDE;
   virtual bool CancelById(const std::string& notification_id) OVERRIDE;
   virtual std::set<std::string> GetAllIdsByProfileAndSourceOrigin(
       Profile* profile,
       const GURL& source) OVERRIDE;
   virtual bool CancelAllBySourceOrigin(const GURL& source_origin) OVERRIDE;
   virtual bool CancelAllByProfile(Profile* profile) OVERRIDE;
   virtual void CancelAll() OVERRIDE;
 
   void GetQueuedNotificationsForTesting(
     std::vector<const Notification*>* notifications);
@@ skipping 42 matching lines @@
   content::NotificationRegistrar registrar_;
 
   // Used by screen-saver and full-screen handling support.
   bool is_user_active_;
   base::RepeatingTimer<NotificationUIManagerImpl> user_state_check_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(NotificationUIManagerImpl);
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_UI_MANAGER_IMPL_H_