chromium/chrome/test/data/websocket/check-hsts.html

<!DOCTYPE html>
<title>Testing HSTS with WebSockets</title>
<script>
var ws_url = window.location.hash.substring(1);
var ws = new WebSocket(ws_url);

ws.onopen = function()
{
  // The fact that the WebSocket connect opened successfully means that SSL was
  // used.
  document.title = 'PASS';
}

ws.onclose = function(evt)
{
  if (!evt.wasClean)
    document.title = 'FAIL';
}
</script>