[XHR] Reset m_downloadedBlobLength

Source/core/xml/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 941 matching lines @@
     m_receivedLength = 0;
 
     m_response = ResourceResponse();
 
     m_responseText.clear();
 
     m_createdDocument = false;
     m_responseDocument = nullptr;
 
     m_responseBlob = nullptr;
+    m_downloadedBlobLength = 0;
 
     m_responseStream = nullptr;
 
     // These variables may referred by the response accessors. So, we can clear
     // this only when we clear the response holder variables above.
     m_binaryResponseBuilder.clear();
     m_responseArrayBuffer.clear();
 }
 
 void XMLHttpRequest::clearRequest()
@@ skipping 449 matching lines @@
 {
     return EventTargetNames::XMLHttpRequest;
 }
 
 ExecutionContext* XMLHttpRequest::executionContext() const
 {
     return ActiveDOMObject::executionContext();
 }
 
 } // namespace WebCore