chromium/third_party/blink/web_tests/media/controls-strict.html

<!DOCTYPE HTML>
<html>
    <head>
        <script src="media-file.js"></script>
        <script src="video-paint-test.js"></script>
        <script src="media-controls.js"></script>
    </head>
    <body onload="setVideoSrcAndWaitForFirstFrame('content/test.ogv')">
        <p>Drawing the controls in strict mode.</p>
        <video controls></video>
    </body>
    <script>
      const video = document.querySelector('video');
      enableTestMode(video);
    </script>
</html>