Avoid referencing an HTMLMediaElement if is currently being deleted

Source/core/dom/GenericEventQueue.cpp

 /*
  * Copyright (C) 2012 Victor Carbune (victor@rosedu.org)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 82 matching lines @@
 }
 
 void GenericEventQueue::close()
 {
     m_isClosed = true;
 
     m_timer.stop();
     m_pendingEvents.clear();
 }
 
+bool GenericEventQueue::enqueueEventWithoutTarget(PassRefPtr<Event> event)
+{
+    if (m_isClosed)
+        return false;
+
+    ASSERT(!event->target());
+
+    m_pendingEvents.append(event);
+
+    if (!m_timer.isActive())
+        m_timer.startOneShot(0);
+
+    return true;
+}
+
 void GenericEventQueue::cancelAllEvents()
 {
     m_timer.stop();
     m_pendingEvents.clear();
 }
 
 bool GenericEventQueue::hasPendingEvents() const
 {
     return m_pendingEvents.size();
 }
 
 }