Support notifications with custom content

ui/message_center/views/message_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_MESSAGE_VIEW_H_
 #define UI_MESSAGE_CENTER_VIEWS_MESSAGE_VIEW_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 82 matching lines @@
 
  protected:
   // Overridden from views::SlideOutView:
   void OnSlideOut() override;
 
   // Creates and add close button to view hierarchy when necessary. Derived
   // classes should call this after its view hierarchy is populated to ensure
   // it is on top of other views.
   void CreateOrUpdateCloseButtonView(const Notification& notification);
 
+  // Changes the background color being used by |background_view_| and schedules
+  // a paint.
+  virtual void SetDrawBackgroundAsActive(bool active);
+
+  views::View* background_view() { return background_view_; }
   views::ImageView* small_image() { return small_image_view_.get(); }
   views::ImageButton* close_button() { return close_button_.get(); }
   views::ScrollView* scroller() { return scroller_; }
   MessageCenterController* controller() { return controller_; }
 
  private:
-  // Changes the background color being used by |background_view_| and schedules
-  // a paint.
-  void SetDrawBackgroundAsActive(bool active);
-
   MessageCenterController* controller_;  // Weak, lives longer then views.
   std::string notification_id_;
   NotifierId notifier_id_;
   views::View* background_view_ = nullptr;  // Owned by views hierarchy.
   std::unique_ptr<views::ImageView> small_image_view_;
   std::unique_ptr<views::ImageButton> close_button_;
   views::ScrollView* scroller_ = nullptr;
 
   base::string16 accessible_name_;
 
   base::string16 display_source_;
 
   std::unique_ptr<views::Painter> focus_painter_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageView);
 };
 
 }  // namespace message_center
 
 #endif // UI_MESSAGE_CENTER_VIEWS_MESSAGE_VIEW_H_