Consider marking event handler as 'passive' to make the page more responsive
<p>I am using hammer for dragging and it is getting choppy when loading other stuff, as this warning message is telling me.</p>

<blockquote>
  <p>Handling of 'touchstart' input event was delayed for X ms due to
  main thread being busy. Consider marking event handler as 'passive' to
  make the page more responsive.</p>
</blockquote>

<p>So I tried to add 'passive' to the listener like so</p>

<pre><code>Hammer(element[0]).on("touchstart", function(ev) {
  // stuff
}, {
  passive: true
});
</code></pre>

<p>but I'm still getting this warning.</p>