Support notifications with custom content

ui/message_center/views/notification_view.h

Index: ui/message_center/views/notification_view.h
diff --git a/ui/message_center/views/notification_view.h b/ui/message_center/views/notification_view.h
index 304475a3fb85e7fb2762ddad06181e76b0399b08..e534da7a753348b019a37f9ec4dd5cf706530249 100644
--- a/ui/message_center/views/notification_view.h
+++ b/ui/message_center/views/notification_view.h
@@ -30,16 +30,14 @@ class PaddedButton;
 class ProportionalImageView;
 
 // View that displays all current types of notification (web, basic, image, and
-// list). Future notification types may be handled by other classes, in which
-// case instances of those classes would be returned by the Create() factory
-// method below.
+// list) except the custom notification. Future notification types may be
+// handled by other classes, in which case instances of those classes would be
+// returned by the Create() factory method below.
 class MESSAGE_CENTER_EXPORT NotificationView
     : public MessageView,
       public views::ViewTargeterDelegate {
  public:
-  // Creates appropriate MessageViews for notifications. Those currently are
-  // always NotificationView instances but in the future
-  // may be instances of other classes, with the class depending on the
+  // Creates appropriate MessageViews for notifications depending on the
   // notification type. A notification is top level if it needs to be rendered
   // outside the browser window. No custom shadows are created for top level
   // notifications on Linux with Aura.