Mark the Notification as being closed before dispatching the event.

Source/modules/notifications/Notification.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 121 matching lines @@
     dispatchEvent(Event::create(EventTypeNames::click));
 }
 
 void Notification::dispatchErrorEvent()
 {
     dispatchEvent(Event::create(EventTypeNames::error));
 }
 
 void Notification::dispatchCloseEvent()
 {
+    m_state = NotificationStateClosed;
     dispatchEvent(Event::create(EventTypeNames::close));
-    m_state = NotificationStateClosed;
 }
 
 TextDirection Notification::direction() const
 {
     // FIXME: Resolve dir()=="auto" against the document.
     return dir() == "rtl" ? RTL : LTR;
 }
 
 const String& Notification::permissionString(WebNotificationPermission permission)
 {
@@ skipping 54 matching lines @@
 
     m_asyncRunner.stop();
 }
 
 bool Notification::hasPendingActivity() const
 {
     return m_state == NotificationStateShowing || m_asyncRunner.isActive();
 }
 
 } // namespace blink