Allow XHR timeout attribute to be overridden after send(), per spec

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 326 matching lines @@
 }
 
 void XMLHttpRequest::setTimeout(unsigned long timeout, ExceptionState& exceptionState)
 {
     // FIXME: Need to trigger or update the timeout Timer here, if needed. http://webkit.org/b/98156
     // XHR2 spec, 4.7.3. "This implies that the timeout attribute can be set while fetching is in progress. If that occurs it will still be measured relative to the start of fetching."
     if (executionContext()->isDocument() && !m_async) {
         exceptionState.throwDOMException(InvalidAccessError, "Timeouts cannot be set for synchronous requests made from a document.");
         return;
     }
+
     m_timeoutMilliseconds = timeout;
+
+    // From http://www.w3.org/TR/XMLHttpRequest/#the-timeout-attribute:
+    // Note: This implies that the timeout attribute can be set while fetching is in progress. If
+    // that occurs it will still be measured relative to the start of fetching.
+    //
+    // The timeout may be overridden after send.
+    if (m_loader)
+        m_loader->overrideTimeout(timeout);
 }
 
 void XMLHttpRequest::setResponseType(const String& responseType, ExceptionState& exceptionState)
 {
     if (m_state >= LOADING) {
         exceptionState.throwDOMException(InvalidStateError, "The response type cannot be set if the object's state is LOADING or DONE.");
         return;
     }
 
     // Newer functionality is not available to synchronous requests in window contexts, as a spec-mandated
@@ skipping 1060 matching lines @@
 }
 
 void XMLHttpRequest::trace(Visitor* visitor)
 {
     visitor->trace(m_responseBlob);
     visitor->trace(m_responseStream);
     visitor->trace(m_progressEventThrottle);
 }
 
 } // namespace WebCore