chromium/third_party/blink/web_tests/http/tests/xmlhttprequest/resources/access-control-allow-with-delay.php

<?php
    sleep(1);
    header("Content-Type: text/plain");
    header("Cache-Control: no-store");
    header("Access-Control-Allow-Origin: *");
    header("Access-Control-Allow-Headers: foo");
?>