chromium/third_party/blink/web_tests/fast/forms/password/password-script-expected.html

<input type="text" id="passwd" style="-webkit-text-security:disc;">
<script>
    var passwd = document.getElementById("passwd");
    passwd.focus();
    eventSender.keyDown('a');
    eventSender.keyDown('F8', ['altKey']);
    passwd.value = "123";
</script>