Deprecate support for xhr.withCredentials for synchronous requests

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

Index: LayoutTests/http/tests/inspector/network-test.js
diff --git a/LayoutTests/http/tests/inspector/network-test.js b/LayoutTests/http/tests/inspector/network-test.js
index 9657da07fe54ec83191198504b42f474815b0d08..ae59ab2a5bda9172a19f95760241f56249c2af10 100644
--- a/LayoutTests/http/tests/inspector/network-test.js
+++ b/LayoutTests/http/tests/inspector/network-test.js
@@ -91,7 +91,8 @@ function makeXHR(method, url, async, user, password, headers, withCredentials, p
         }
     }
     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);