Web Notifications should always reappear as popups when updated.

ui/message_center/notification_list.cc

 // 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.
 
 #include "ui/message_center/notification_list.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/time/time.h"
@@ skipping 82 matching lines @@
     const std::string& old_id,
     scoped_ptr<Notification> new_notification) {
   Notifications::iterator iter = GetNotification(old_id);
   if (iter == notifications_.end())
     return;
 
   new_notification->CopyState(*iter);
 
   // Handles priority promotion. If the notification is already dismissed but
   // the updated notification has higher priority, it should re-appear as a
-  // toast.
-  if ((*iter)->priority() < new_notification->priority()) {
+  // toast. Notifications coming from websites through the Web Notification API
+  // will always re-appear on update.
+  if ((*iter)->priority() < new_notification->priority() ||
+      new_notification->notifier_id().type == NotifierId::WEB_PAGE) {
     new_notification->set_is_read(false);
     new_notification->set_shown_as_popup(false);
   }
 
   // Do not use EraseNotification and PushNotification, since we don't want to
   // change unread counts nor to update is_read/shown_as_popup states.
   Notification* old = *iter;
   notifications_.erase(iter);
   delete old;
 
@@ skipping 228 matching lines @@
     notification->set_shown_as_popup(message_center_visible_
                                      || quiet_mode_
                                      || notification->shown_as_popup());
   }
   // Take ownership. The notification can only be removed from the list
   // in EraseNotification(), which will delete it.
   notifications_.insert(notification.release());
 }
 
 }  // namespace message_center