pressed-state-changed.html | Explore in Territory

<!DOCTYPE html>
<html>
<body>
<input id="c" type="button" aria-pressed="false" aria-label="My Button">
<script>
  function go() {
    document.getElementById('c').setAttribute('aria-pressed', 'true');
  }
</script>
</body>
</html>

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