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 https://xhr.spec.whatwg.org/.
Tests the special case of whitelisting all origins.

Testing: http://localhost:8000/xmlhttprequest/resources/get.txt (sync)
PASS: PASS
Testing: http://localhost:8000/xmlhttprequest/resources/get.txt (async)
PASS: PASS
Testing: http://127.0.0.1:8000/xmlhttprequest/resources/get.txt (sync)
PASS: PASS
Testing: http://127.0.0.1:8000/xmlhttprequest/resources/get.txt (async)
PASS: PASS