Fix accessability for web notification tray.

ash/system/web_notification/web_notification_tray.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 ASH_SYSTEM_NOTIFICATION_WEB_NOTIFICATION_TRAY_H_
 #define ASH_SYSTEM_NOTIFICATION_WEB_NOTIFICATION_TRAY_H_
 
 #include "ash/ash_export.h"
 #include "ash/system/tray/tray_background_view.h"
 #include "ash/system/user/login_status.h"
@@ skipping 107 matching lines @@
 
   // Returns true if the message center bubble is visible.
   bool IsMessageCenterBubbleVisible() const;
 
   // Returns true if the mouse is inside the notification bubble.
   bool IsMouseInNotificationBubble() const;
 
   // Overridden from TrayBackgroundView.
   virtual void SetShelfAlignment(ShelfAlignment alignment) OVERRIDE;
   virtual void AnchorUpdated() OVERRIDE;
+  virtual string16 GetAccessibleName() OVERRIDE;
 
   // Overridden from internal::ActionableView.
   virtual bool PerformAction(const ui::Event& event) OVERRIDE;
 
  protected:
   // Send a remove request to the delegate.
   void SendRemoveNotification(const std::string& id);
 
   // Send a remove request for all notifications to the delegate.
   void SendRemoveAllNotifications();
@@ skipping 35 matching lines @@
   views::Label* count_label_;
   Delegate* delegate_;
   bool show_message_center_on_unlock_;
 
   DISALLOW_COPY_AND_ASSIGN(WebNotificationTray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_NOTIFICATION_WEB_NOTIFICATION_TRAY_H_