Google Tag - User Timings

gtag.html

<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=UA-xxxxxxx-xx"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('set',{'content_group1':'{{page.title}}'});
if (window.performance) {
  var timeSincePageLoad = Math.round(performance.now());
  gtag('event', 'timing_complete', {
    'name': 'load',
    'value': timeSincePageLoad,
    'event_category': 'Page Render Time'
  });
}  gtag('config', 'UA-xxxxxxx-xx');
</script>