Oilpan: Allocate all EventTarget derived types on the manged heap.

Source/core/xml/XMLHttpRequestUpload.cpp

 /*
  * Copyright (C) 2008 Apple 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 54 matching lines @@
     dispatchEvent(XMLHttpRequestProgressEvent::create(EventTypeNames::loadend, lengthComputable, bytesSent, total));
 }
 
 void XMLHttpRequestUpload::handleRequestError(const AtomicString& type)
 {
     bool lengthComputable = m_lastTotalBytesToBeSent > 0 && m_lastBytesSent <= m_lastTotalBytesToBeSent;
     dispatchEvent(XMLHttpRequestProgressEvent::create(EventTypeNames::progress, lengthComputable, m_lastBytesSent, m_lastTotalBytesToBeSent));
     dispatchEventAndLoadEnd(type, lengthComputable, m_lastBytesSent, m_lastTotalBytesToBeSent);
 }
 
+void XMLHttpRequestUpload::trace(Visitor* visitor)
+{
+    visitor->trace(m_xmlHttpRequest);
+    XMLHttpRequestEventTarget::trace(visitor);
+}
+
 } // namespace WebCore