<!DOCTYPE html>
<html>
<head>
  <style>
    :read-only::-webkit-scrollbar {
      --a: var(--b), var(--c);
    }
  </style>
  <script>
    if (window.testRunner) {
        testRunner.waitUntilDone();
        testRunner.dumpAsText();
    }
    onload = async () => {
      let timer = null;
      visualViewport.onresize = () => {
        document.execCommand('Outdent');
        if (timer)
            return;
        timer = setTimeout(function() {
            document.documentElement.innerHTML = "<body>Test passes if it does not crash.</body>";
            testRunner.notifyDone();
        }, 50);
      };
      let blockquote = document.createElement('blockquote');
      document.body.append(blockquote);
      let p = document.createElement('p');
      blockquote.append(p);
      document.body.append(document.createElement('object'));
      blockquote.append(document.createElement('iframe'));
      let blockquote2 = document.createElement('blockquote');
      document.documentElement.append(document.createElement('object'));
      p.append(blockquote2);
      blockquote2.append(document.createElement('iframe'));
      document.body.innerHTML += '';
      document.execCommand('SelectAll');
      let animation = new Animation();
      animation.play();
      await animation.ready;
      document.designMode = 'on';
      if (window.caches)
        await caches.has('d');
      document.body.replaceChildren();
    };
  </script>
</head>
<body>
</body>
</html>
