chromium/third_party/blink/web_tests/external/wpt/mediacapture-streams/MediaStreamTrack-transfer-video.https.html

<!doctype html>
<title>MediaStreamTrack transfer to iframe</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script>
promise_test(async () => {
  const iframe = document.createElement("iframe");
  const stream = await navigator.mediaDevices.getUserMedia({video: true});
  const track = stream.getVideoTracks()[0];
  const result = new Promise((resolve, reject) => {
    window.onmessage = (e) => {
      if (e.data.result === 'Failure') {
        reject('Failed: ' + e.data.error);
      } else {
        resolve();
      }
    };
  });
  iframe.addEventListener("load", () => {
    iframe.contentWindow.postMessage(track);
  });
  iframe.src = "support/iframe-MediaStreamTrack-transfer-video.html";
  document.body.appendChild(iframe);
  return result;
});
</script>