CONSOLE WARNING: Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check http://xhr.spec.whatwg.org/.
This test checks that no exception is raised when getting a 404 HTTP response - that's success from XHR point of view.

PASS: No exception.
readyState: 4 (number)
responseText: Non-empty (string)
responseXML: null (object)
status: 404 (number)
statusText: Not Found (string)