chromium/src/third_party/blink/web_tests/fast/forms/password/password-alt-f8-twice.html

<input type="password" id="passwd">

<script>
    // This verifies pressing hotkey Alt-F8 twice can obscure the password again.
    document.getElementById("passwd").focus();
    eventSender.keyDown('a');
    eventSender.keyDown('F8', ['altKey']);
    eventSender.keyDown('F8', ['altKey']);
</script>