chromium/chrome/test/data/prerender/service_worker.html

<html>
<head>
  <title>ServiceWorker Loader</title>
  <script type="text/javascript">
    window.addEventListener('load', function() {
      navigator.serviceWorker.register('/prerender/service_worker.js')
        .then(function(registration) {
          console.log('ServiceWorker registered');
          return navigator.serviceWorker.ready;
        })
        .then(function(registration) {
          document.title = 'SW READY';
        })
        .catch(function(err) {
          console.log(err);
        });
    });
  </script>
<head>
<body></body>
</html>