Break core/platform/network dependency on core

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 683 matching lines @@
 }
 
 void XMLHttpRequest::send(DOMFormData* body, ExceptionState& es)
 {
     LOG(Network, "XMLHttpRequest %p send() DOMFormData %p", this, body);
 
     if (!initSend(es))
         return;
 
     if (areMethodAndURLValidForSend()) {
-        m_requestEntityBody = FormData::createMultiPart(*(static_cast<FormDataList*>(body)), body->encoding());
+        m_requestEntityBody = body->createMultiPartFormData(body->encoding());
 
         String contentType = getRequestHeader("Content-Type");
         if (contentType.isEmpty()) {
             contentType = String("multipart/form-data; boundary=") + m_requestEntityBody->boundary().data();
             setRequestHeaderInternal("Content-Type", contentType);
         }
     }
 
     createRequest(es);
 }
@@ skipping 659 matching lines @@
 {
     return EventTargetNames::XMLHttpRequest;
 }
 
 ExecutionContext* XMLHttpRequest::executionContext() const
 {
     return ActiveDOMObject::executionContext();
 }
 
 } // namespace WebCore