origin-header-same-origin-post-sync.html

<html>
<body>
<pre id="console"></pre>
<script>
function log(message) {
    document.getElementById('console').appendChild(document.createTextNode(message + '\n'));
}

if (window.testRunner)
    testRunner.dumpAsText();

var xhr = new XMLHttpRequest();
xhr.open('POST', 'resources/access-control-basic-allow-access-control-origin-header.cgi', false);
xhr.send(null);
log(xhr.responseText);
</script>
</body>
</html>

chromium/third_party/blink/web_tests/http/tests/xmlhttprequest/origin-header-same-origin-post-sync.html