<!DOCTYPE html>
<meta charset=utf-8>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/common/get-host-info.sub.js"></script>
<!-- Pull in the with_iframe helper function from the service worker tests -->
<script src="/service-workers/service-worker/resources/test-helpers.sub.js"></script>
<body>
<script>

const events = [];

function testCompletion(t) {
  return new Promise((resolve) => {
    window.addEventListener("message", t.step_fun