Carve out an exception for embedded credentials in XHR.

third_party/WebKit/LayoutTests/http/tests/xmlhttprequest/failed-auth.html

 <p>Test for <a href="http://bugs.webkit.org/show_bug.cgi?id=13075">bug 13075</a>:
 XMLHttpRequest with failed authentication should set status to 401.</p>
 <ol>
   <li>Sync, no credentials:
   <li>Sync, incorrect credentials:
   <li>Async, no credentials: 
   <li>Async, incorrect credentials: 
 </ol>
 <script>
 function checkResult(n, code) {
     document.getElementsByTagName("li")[n - 1].firstChild.nodeValue += 
         ((code == 401) ? " OK" : (" " + code + " != 401"));
 }
 
-function checkFailure(n, code) {
-    document.getElementsByTagName("li")[n - 1].firstChild.nodeValue += 
-        ((code == 0) ? " OK" : (" " + code + " != 0"));
-}
-
 function log(n, message) {
     document.getElementsByTagName("li")[n - 1].firstChild.nodeValue += 
         " " + message;
 }
 
 
 if (window.testRunner) {
     testRunner.dumpAsText();
     testRunner.waitUntilDone();
 } else {
@@ skipping 32 matching lines @@
     log(3, ex);
     test4();
 }
 
 function test4() {
     try {
         var r = new XMLHttpRequest();
         r.open("GET", "resources/basic-auth/basic-auth.php?uid=login4", true, "badname", "passpw");
         r.onreadystatechange = function() {
           if (r.readyState == 4) {
-            checkFailure(4, r.status);
+            checkResult(4, r.status);
             testRunner.notifyDone();
           }
         };
         r.send();
     } catch (ex) {
         log(4, ex);
         testRunner.notifyDone();
     }
 }
 </script>