revert module wait

Author: Elliott Marquez

test/unit/disable-upgrade.html

@@ -185,10 +185,9 @@ <h2 id="element">[[prop]]</h2>
 suite('disable-upgrade', function() {
   let el;
 
-  setup((done) => {
+  setup(() => {
     el = document.createElement('my-element');
     document.body.appendChild(el);
-    window.addEventListener('DOMContentLoaded', function() { done(); });
   });
   teardown(function() {
     document.body.removeChild(el);