[Download Notification] Use NotificationUIManager instead of MessageCenter

chrome/browser/notifications/message_center_notification_manager.cc

Index: chrome/browser/notifications/message_center_notification_manager.cc
diff --git a/chrome/browser/notifications/message_center_notification_manager.cc b/chrome/browser/notifications/message_center_notification_manager.cc
index 5e7802d4edf8e2d1e8f9adc2eb3a787afec20def..b5cb0554fc880b4eeaa80a2e174947343eedc98c 100644
--- a/chrome/browser/notifications/message_center_notification_manager.cc
+++ b/chrome/browser/notifications/message_center_notification_manager.cc
@@ -201,7 +201,14 @@ const Notification* MessageCenterNotificationManager::FindById(
       profile_notifications_.find(profile_notification_id);
   if (iter == profile_notifications_.end())
     return NULL;
-  return &(iter->second->notification());
+
+  // Update |notification| with the latest information from the message center.

[Jun Mukai, 2015/03/31 19:59:47]

This is weird. Is there some case where the state is inconsistent among message
center and the MessageCenterNotificationManager?
We should fix the inconsistency.

[yoshiki, 2015/04/01 04:10:49]

"shown_as_popup" and "read" flags are changed in the message center
(message_center::NotificationList) internally, and we need to sync them at
least.

[Jun Mukai, 2015/04/01 18:02:11]

Commented on the other part.
I believe FindById should not update anything on each notification, it's a
method to lookup existing ones.

Another suggestion is:
return
message_center_->FindVisibleNotificationById(iter->second->notification().id());

[yoshiki, 2015/04/06 02:22:18]

Thank you for the suggestion but we can't do it. FindVisibleNotificationById
returns the parent class (message_center::Notification), but FindById need to
return the child class (Notification defined in chrome/browser).

+  ProfileNotification* profile_notification = iter->second;
+  profile_notification->CopyNotificationState(
+      message_center_->FindVisibleNotificationById(
+          iter->second->notification().id()));
+
+  return &(profile_notification->notification());
 }
 
 bool MessageCenterNotificationManager::CancelById(