Oilpan: Move the EventListener hierarchy to Oilpan's heap

Source/modules/webmidi/MIDIAccess.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 56 matching lines @@
 
 MIDIAccess::~MIDIAccess()
 {
 }
 
 EventListener* MIDIAccess::onstatechange()
 {
     return getAttributeEventListener(EventTypeNames::statechange);
 }
 
-void MIDIAccess::setOnstatechange(PassRefPtr<EventListener> listener)
+void MIDIAccess::setOnstatechange(PassRefPtrWillBeRawPtr<EventListener> listener)
 {
     m_hasPendingActivity = listener;
     setAttributeEventListener(EventTypeNames::statechange, listener);
 }
 
 bool MIDIAccess::hasPendingActivity() const
 {
     return m_hasPendingActivity && !executionContext()->activeDOMObjectsAreStopped();
 }
 
@@ skipping 114 matching lines @@
 
 DEFINE_TRACE(MIDIAccess)
 {
     visitor->trace(m_inputs);
     visitor->trace(m_outputs);
     RefCountedGarbageCollectedEventTargetWithInlineData<MIDIAccess>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink