Deprecate support for xhr.withCredentials for synchronous requests

LayoutTests/http/tests/inspector/network-test.js

 // This goes before everything else to keep console message line number invariant.
 var lastXHRIndex = 0;
 function xhrLoadedCallback()
 {
     // We need to make sure the console message text is unique so that we don't end up with repeat count update only.
     console.log("XHR loaded: " + (++lastXHRIndex));
 }
 
 var initialize_NetworkTest = function() {
 
@@ skipping 73 matching lines @@
     var xhr = new XMLHttpRequest();
     xhr.responseType = type;
     xhr.onreadystatechange = function()
     {
         if (xhr.readyState === XMLHttpRequest.DONE) {
             if (typeof(callback) === "function")
                 callback();
         }
     }
     xhr.open(method, url, async, user, password);
-    xhr.withCredentials = withCredentials;
+    if (async)

[tyoshino (SeeGerritForStatus), 2014/06/17 02:19:49]

I think we should catch bad combination of arguments from a buggy test case. How
about throwing when !async && withCredentials?

[tyoshino (SeeGerritForStatus), 2014/06/19 08:31:13]

Reminder. (it's ok to skip it as it was drive-by comment, but want to hear some
answer)

+        xhr.withCredentials = withCredentials;
     for (var  i = 0; i < headers.length; ++i)
         xhr.setRequestHeader(headers[i][0], headers[i][1]);
     xhr.send(payload);
 }
 
 function makeXHRForJSONArguments(jsonArgs)
 {
     var args = JSON.parse(jsonArgs);
     makeXHR(args.method, args.url, args.async, args.user, args.password, args.headers || [], args.withCredentials, args.payload, args.type, xhrLoadedCallback);
 }
 
 
 function resetInspectorResourcesData()
 {
     if (!window.internals)
         return false;
 
     internals.setInspectorResourcesDataSizeLimits(10 * 1000 * 1000, 1000 * 1000);
     return true;
 }