chromium/content/test/data/accessibility/event/disabled-state-changed.html

<!-- On a submit button, changing the disabled state should also change its default state -->
<!DOCTYPE html>
<html>
<body>
<input id="b1" type="submit" value="Button 1 turns disabled on">
<input id="b2" type="submit" disabled value="Button 2 turns disabled off">
<script>
  function go() {
    document.getElementById('b1').disabled = true;
    document.getElementById('b2').disabled = false;
  }
</script>
</body>
</html>