Show no-notification message in the bottom label of message center

ui/message_center/views/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 UI_MESSAGE_CENTER_VIEWS_MESSAGE_CENTER_BUBBLE_H_
 #define UI_MESSAGE_CENTER_VIEWS_MESSAGE_CENTER_BUBBLE_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
@@ skipping 37 matching lines @@
  private:
   MessageCenterView* message_center_view_;
 
   // Use settings view as the initially visible content if true.
   bool initially_settings_visible_;
 
   // True if the first message which gets shown should have no margin against
   // the used anchor.
   bool first_item_has_no_margin_;
 
-  base::string16 title_;
-
   DISALLOW_COPY_AND_ASSIGN(MessageCenterBubble);
 };
 
 }  // namespace message_center
 
 #endif  // UI_MESSAGE_CENTER_VIEWS_MESSAGE_CENTER_BUBBLE_H_