chromium/chrome/test/data/media/picture-in-picture/autopip-camera.html

<!DOCTYPE html>

<head>
  <meta charset="utf-8">
  <title>Autopip Document Picture-in-Picture with Camera and Microphone</title>
  <script src="../../webrtc/test_functions.js"></script>
  <script src="../../webrtc/getusermedia.js"></script>
</head>

<body></body>
<script>
  function openPip({ width = 300, height = 300, disallowReturnToOpener, preferInitialWindowPlacement } = {}) {
    documentPictureInPicture.requestWindow({ width, height, disallowReturnToOpener, preferInitialWindowPlacement });
  }

  navigator.mediaSession.setActionHandler('enterpictureinpicture', openPip);
</script>