CONSOLE WARNING: line 15: 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/.
This test verifies that XMLHttpRequest properly handles Content-Type when it is reused.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".

PASS req.getResponseHeader('Content-Type') is "text/plain; charset=utf-8"
PASS req.responseText is "Проверка"
PASS req.getResponseHeader('Content-Type') is "text/plain; charset=windows-1251"
PASS req.responseText is "Проверка"
PASS successfullyParsed is true

TEST COMPLETE