chromium/third_party/blink/web_tests/fast/forms/interactive-validation-assertion-by-validate-twice.html

<!DOCTYPE html>
<head>
<script src="../../resources/js-test.js"></script>
</head>
<body>

<p>Test a bug that an assertion fails by invoking interactive validation twice very quickly.</p>

<form>
<input required style="float:left">
<input type=submit id=submit>
</form>

<div id=console></div>

<script>
var submit = document.getElementById('submit');
window.jsTestIsAsync = true;

submit.click();
setTimeout(delayedSubmit, 0);

function delayedSubmit() {
    submit.click();
    testPassed('Not crashed.');
    finishJSTest();
}
</script>
</body>