[v8 gc] Introduce a base class for all objects that can have pending activity

third_party/WebKit/Source/core/xmlhttprequest/XMLHttpRequest.cpp

 /*
  *  Copyright (C) 2004, 2006, 2008 Apple Inc. All rights reserved.
  *  Copyright (C) 2005-2007 Alexey Proskuryakov <ap@webkit.org>
  *  Copyright (C) 2007, 2008 Julien Chaffraix <jchaffraix@webkit.org>
  *  Copyright (C) 2008, 2011 Google Inc. All rights reserved.
  *  Copyright (C) 2012 Intel Corporation
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
@@ skipping 184 matching lines @@
 
 XMLHttpRequest* XMLHttpRequest::create(ExecutionContext* context)
 {
     XMLHttpRequest* xmlHttpRequest = new XMLHttpRequest(context, nullptr);
     xmlHttpRequest->suspendIfNeeded();
 
     return xmlHttpRequest;
 }
 
 XMLHttpRequest::XMLHttpRequest(ExecutionContext* context, PassRefPtr<SecurityOrigin> isolatedWorldSecurityOrigin)
-    : ActiveDOMObject(context)
+    : ActiveScriptWrappable(this)
+    , ActiveDOMObject(context)
     , m_timeoutMilliseconds(0)
     , m_state(UNSENT)
     , m_lengthDownloadedToFile(0)
     , m_receivedLength(0)
     , m_exceptionCode(0)
     , m_progressEventThrottle(XMLHttpRequestProgressEventThrottle::create(this))
     , m_responseTypeCode(ResponseTypeDefault)
     , m_isolatedWorldSecurityOrigin(isolatedWorldSecurityOrigin)
     , m_eventDispatchRecursionLevel(0)
     , m_async(true)
@@ skipping 1486 matching lines @@
     visitor->trace(m_responseDocumentParser);
     visitor->trace(m_progressEventThrottle);
     visitor->trace(m_upload);
     visitor->trace(m_blobLoader);
     XMLHttpRequestEventTarget::trace(visitor);
     DocumentParserClient::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink