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

Source/WebCore/xml/XMLHttpRequestProgressEvent.h

 /*
  * Copyright (C) 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Julien Chaffraix <jchaffraix@webkit.org>. 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
@@ skipping 32 matching lines @@
         return adoptRef(new XMLHttpRequestProgressEvent(type, lengthComputable, loaded, total));
     }
 
     // Those 2 synonyms are included for compatibility with Firefox.
     unsigned long long position() const { return loaded(); }
     unsigned long long totalSize() const { return total(); }
 
     virtual const AtomicString& interfaceName() const { return eventNames().interfaceForXMLHttpRequestProgressEvent; }
 
 private:
-    XMLHttpRequestProgressEvent() { }
+    XMLHttpRequestProgressEvent()
+    {
+        ScriptWrappable::init(this);
+    }
+
     XMLHttpRequestProgressEvent(const AtomicString& type, bool lengthComputable, unsigned long long loaded, unsigned long long total)
         : ProgressEvent(type, lengthComputable, loaded, total)
     {
+        ScriptWrappable::init(this);
     }
 };
 
 } // namespace WebCore
 
 #endif // XMLHttpRequestProgressEvent_h