Add UpdateNotificationSize to MessageCenterController.

ui/message_center/views/message_center_controller.h

Index: ui/message_center/views/message_center_controller.h
diff --git a/ui/message_center/views/message_center_controller.h b/ui/message_center/views/message_center_controller.h
index 9ff85a52c2fbae4c9911b99d41479071d6ae60b2..a39e36aba72ecc442bf24421a6c0ba25a206c180 100644
--- a/ui/message_center/views/message_center_controller.h
+++ b/ui/message_center/views/message_center_controller.h
@@ -30,6 +30,11 @@ class MessageCenterController {
   virtual void ClickOnNotificationButton(const std::string& notification_id,
                                          int button_index) = 0;
   virtual void ClickOnSettingsButton(const std::string& notification_id) = 0;
+  // For ArcCustomNotificationView, size changes might come after the
+  // notification update over Mojo. Provide a method here to notify when
+  // a notification changed in some way and needs to be laid out again.
+  // See crbug.com/690813.
+  virtual void ShouldUpdateNotification(const std::string& notification_id) = 0;

[xiyuan, 2017/02/13 21:54:07]

nit: ShouldUpdateNotification -> UpdateNotification

Drop prefix "Should" to make it more clear that it performs some action.

[Eliot Courtney, 2017/02/14 02:25:53]

Done.

 };
 
 }  // namespace message_center