Oilpan: Move the EventListener hierarchy to Oilpan's heap

Source/modules/webmidi/MIDIAccess.h

 /*
  * 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 47 matching lines @@
         MIDIAccess* access = new MIDIAccess(accessor, sysexEnabled, ports, executionContext);
         access->suspendIfNeeded();
         return access;
     }
     ~MIDIAccess() override;
 
     MIDIInputMap* inputs() const;
     MIDIOutputMap* outputs() const;
 
     EventListener* onstatechange();
-    void setOnstatechange(PassRefPtr<EventListener>);
+    void setOnstatechange(PassRefPtrWillBeRawPtr<EventListener>);
 
     bool sysexEnabled() const { return m_sysexEnabled; }
 
     // EventTarget
     const AtomicString& interfaceName() const override { return EventTargetNames::MIDIAccess; }
     ExecutionContext* executionContext() const override { return ActiveDOMObject::executionContext(); }
 
     // ActiveDOMObject
     bool hasPendingActivity() const override;
     void stop() override;
@@ skipping 26 matching lines @@
     OwnPtr<MIDIAccessor> m_accessor;
     bool m_sysexEnabled;
     bool m_hasPendingActivity;
     HeapVector<Member<MIDIInput>> m_inputs;
     HeapVector<Member<MIDIOutput>> m_outputs;
 };
 
 } // namespace blink
 
 #endif // MIDIAccess_h