Update XMLHttpRequest forbidden header names.

Source/web/tests/AssociatedURLLoaderTest.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 566 matching lines @@
     // Check non-token header fails.
     CheckHeaderFails("foo()");
 
     // Check forbidden headers fail.
     CheckHeaderFails("accept-charset");
     CheckHeaderFails("accept-encoding");
     CheckHeaderFails("connection");
     CheckHeaderFails("content-length");
     CheckHeaderFails("cookie");
     CheckHeaderFails("cookie2");
-    CheckHeaderFails("content-transfer-encoding");
     CheckHeaderFails("date");
+    CheckHeaderFails("dnt");
     CheckHeaderFails("expect");
     CheckHeaderFails("host");
     CheckHeaderFails("keep-alive");
     CheckHeaderFails("origin");
     CheckHeaderFails("referer");
     CheckHeaderFails("te");
     CheckHeaderFails("trailer");
     CheckHeaderFails("transfer-encoding");
     CheckHeaderFails("upgrade");
     CheckHeaderFails("user-agent");
@@ skipping 62 matching lines @@
     m_expectedLoader->loadAsynchronously(request, this);
     serveRequests();
     EXPECT_TRUE(m_didReceiveResponse);
     EXPECT_TRUE(m_didReceiveData);
     EXPECT_TRUE(m_didFinishLoading);
 
     EXPECT_FALSE(m_actualResponse.httpHeaderField(headerNameString).isEmpty());
 }
 
 }