Re-factor Ash Message Center code part 2/4

ash/system/web_notification/message_center_bubble.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_MESSAGE_CENTER_BUBBLE_H_
 #define ASH_SYSTEM_NOTIFICATION_MESSAGE_CENTER_BUBBLE_H_
 
 #include "ash/system/web_notification/web_notification_bubble.h"
 
 namespace ash {
 
 class WebNotificationTray;
 
 namespace message_center {
 
 class MessageCenterContentsView;
 
 // Bubble for message center.
 class MessageCenterBubble : public WebNotificationBubble {
  public:
   explicit MessageCenterBubble(WebNotificationTray* tray);
 
   virtual ~MessageCenterBubble();
 
   size_t NumMessageViewsForTest() const;
 
-  // Overridden from TrayBubbleView::Host.
+  // Overridden from TrayBubbleView::Delegate.
   virtual void BubbleViewDestroyed() OVERRIDE;
 
-  virtual void OnClickedOutsideView() OVERRIDE;
-
  private:
   // Overridden from WebNotificationBubble.
   virtual void UpdateBubbleView() OVERRIDE;
 
   MessageCenterContentsView* contents_view_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageCenterBubble);
 };
 
 }  // namespace message_center
 
 }  // namespace ash
 
 #endif // ASH_SYSTEM_NOTIFICATION_MESSAGE_CENTER_BUBBLE_H_