First part of work to move V8 binding integrity off of vtables.

Source/WebCore/Modules/webaudio/OfflineAudioCompletionEvent.cpp

 /*
  * Copyright (C) 2011, 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:
  * 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 27 matching lines @@
     return adoptRef(new OfflineAudioCompletionEvent);
 }
 
 PassRefPtr<OfflineAudioCompletionEvent> OfflineAudioCompletionEvent::create(PassRefPtr<AudioBuffer> renderedBuffer)
 {
     return adoptRef(new OfflineAudioCompletionEvent(renderedBuffer));
 }
 
 OfflineAudioCompletionEvent::OfflineAudioCompletionEvent()
 {
+    ScriptWrappable::init(this);
 }
 
-
 OfflineAudioCompletionEvent::OfflineAudioCompletionEvent(PassRefPtr<AudioBuffer> renderedBuffer)
     : Event(eventNames().completeEvent, true, false)
     , m_renderedBuffer(renderedBuffer)
 {
+    ScriptWrappable::init(this);
 }
 
 OfflineAudioCompletionEvent::~OfflineAudioCompletionEvent()
 {
 }
 
 const AtomicString& OfflineAudioCompletionEvent::interfaceName() const
 {
     return eventNames().interfaceForOfflineAudioCompletionEvent;
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(WEB_AUDIO)