Fix XMLHttpRequest leak document when send() is called multiple times.

Source/core/xml/XMLHttpRequest.h

 /*
  *  Copyright (C) 2003, 2006, 2008 Apple Inc. All rights reserved.
  *  Copyright (C) 2005, 2006 Alexey Proskuryakov <ap@nypop.com>
  *  Copyright (C) 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
  *  version 2 of the License, or (at your option) any later version.
@@ skipping 57 matching lines @@
 
     enum ResponseTypeCode {
         ResponseTypeDefault,
         ResponseTypeText,
         ResponseTypeJSON,
         ResponseTypeDocument,
         ResponseTypeBlob,
         ResponseTypeArrayBuffer
     };
 
+    enum DropProtection {
+        DropProtectionSync,
+        DropProtectionAsync,
+    };
+
     virtual void contextDestroyed();
     virtual void didTimeout();
     virtual bool canSuspend() const;
     virtual void suspend(ReasonForSuspension);
     virtual void resume();
     virtual void stop();
 
     virtual const AtomicString& interfaceName() const OVERRIDE;
     virtual ScriptExecutionContext* scriptExecutionContext() const OVERRIDE;
 
@@ skipping 74 matching lines @@
     bool initSend(ExceptionState&);
     void sendBytesData(const void*, size_t, ExceptionState&);
 
     String getRequestHeader(const AtomicString& name) const;
     void setRequestHeaderInternal(const AtomicString& name, const String& value);
 
     void changeState(State newState);
     void callReadyStateChangeListener();
     void dropProtectionSoon();
     void dropProtection(Timer<XMLHttpRequest>* = 0);
-    void internalAbort();
+    void internalAbort(DropProtection = DropProtectionSync);
     void clearResponse();
     void clearResponseBuffers();
     void clearRequest();
 
     void createRequest(ExceptionState&);
 
     void genericError();
     void networkError();
     void abortError();
 
@@ skipping 43 matching lines @@
 
     // An enum corresponding to the allowed string values for the responseType attribute.
     ResponseTypeCode m_responseTypeCode;
     Timer<XMLHttpRequest> m_protectionTimer;
     RefPtr<SecurityOrigin> m_securityOrigin;
 };
 
 } // namespace WebCore
 
 #endif // XMLHttpRequest_h