Deprecate support for xhr.withCredentials for synchronous requests

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 468 matching lines @@
     }
 }
 
 void XMLHttpRequest::setWithCredentials(bool value, ExceptionState& exceptionState)
 {
     if (m_state > OPENED || m_loader) {
         exceptionState.throwDOMException(InvalidStateError,  "The value may only be set if the object's state is UNSENT or OPENED.");
         return;
     }
 
+    // FIXME: According to XMLHttpRequest Level 2 we should throw InvalidAccessError exception here.
+    // However for time being only throw warning message to console to give web developers time to update.
+    if (!m_async && executionContext()->isDocument()) {
+        String consoleMessage("Support for withCredentials deprecated for synchronous requests.");

[Inactive, 2014/06/12 13:28:39]

If you do this, you will like need to add a UseCounter as well so that we can
measure usage out there and know if and when it is safe to drop support for
this.

+        executionContext()->addConsoleMessage(JSMessageSource, WarningMessageLevel, consoleMessage);
+        return;
+    }
+
     m_includeCredentials = value;
 }
 
 bool XMLHttpRequest::isAllowedHTTPMethod(const String& method)
 {
     return !equalIgnoringCase(method, "TRACE")
         && !equalIgnoringCase(method, "TRACK")
         && !equalIgnoringCase(method, "CONNECT");
 }
 
@@ skipping 959 matching lines @@
 {
     visitor->trace(m_responseBlob);
     visitor->trace(m_responseStream);
     visitor->trace(m_responseDocument);
     visitor->trace(m_progressEventThrottle);
     visitor->trace(m_upload);
     XMLHttpRequestEventTarget::trace(visitor);
 }
 
 } // namespace WebCore