Adds the contextMessage field to notifications.

ui/message_center/views/notification_view.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_NOTIFICATION_VIEW_H_
 #define UI_MESSAGE_CENTER_VIEWS_NOTIFICATION_VIEW_H_
 
 #include <vector>
 
 #include "ui/message_center/message_center_export.h"
@@ skipping 53 matching lines @@
   bool IsMessageExpansionNeeded(int width);
   int GetMessageLineLimit(int width);
   int GetMessageLines(int width, int limit);
   int GetMessageHeight(int width, int limit);
 
   // Weak references to NotificationView descendants owned by their parents.
   views::View* background_view_;
   views::View* top_view_;
   BoundedLabel* title_view_;
   BoundedLabel* message_view_;
+  BoundedLabel* context_message_view_;
   std::vector<views::View*> item_views_;
   views::View* icon_view_;
   views::View* bottom_view_;
   views::View* image_view_;
   views::ProgressBar* progress_bar_view_;
   std::vector<views::View*> action_buttons_;
 
   DISALLOW_COPY_AND_ASSIGN(NotificationView);
 };
 
 }  // namespace message_center
 
 #endif // UI_MESSAGE_CENTER_VIEWS_NOTIFICATION_VIEW_H_