<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Animate using sibling iframe's timeline</title>
</head>
<body></body>
<script src="/common/get-host-info.sub.js"></script>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script type="text/javascript">
  'use strict';

  function crossSiteUrl(filename) {
    const url =
        get_host_info().HTTP_REMOTE_ORIGIN +
            '/web-animations/timing-model/timelines/resources/' +
            filename;
    return url;
  }

  function loadFrame(name, path, hidden) {
    return new Promise(resolve => {
      const frame = document.createElement('iframe');
      if (hidden)
        frame.style = 'visibility: hidden;';
      frame.name = name;
      document.body.appendChild(frame);
      frame.onload = () => {
        resolve();
      }
      frame.src = crossSiteUrl(path);
    });
  }

 function waitForTestResults() {
    return new Promise(resolve => {
      const listener = (evt) => {
        window.removeEventListener('message', listener);
        resolve(evt.data);
      };
      window.addEventListener('message', listener);
    });
  }

  promise_test(async t => {
    const promise = waitForTestResults().then((data) => {
      assert_equals(data, 'PASS');
    });
    // Animate an element in frame A.
    await loadFrame('a', 'target-frame.html', false);
    // Animation's timeline is in hidden frame B.
    await loadFrame('b', 'timeline-frame.html', true);

   return promise;
  }, 'animation tied to another frame\'s timeline runs properly');
</script>
</html>
