test_file_with_closed_shadow_root.html

<html>
Test file!
<div id="host"> </div>
<script>
  var host = document.getElementById('host');
  var shadowRoot = host.attachShadow({mode: 'closed'});
  shadowRoot.appendChild(document.createElement('div'));
  shadowRoot.appendChild(document.createElement('div'));
</script>
</html>

chromium/chrome/test/data/extensions/test_file_with_closed_shadow_root.html