<script>
  if (window.testRunner)
    window.testRunner.dumpAsText();
  onload = () => {
    document.designMode = 'on';
    document.execCommand('SelectAll');
    getSelection().modify('move', 'right', 'word');
    queueMicrotask(() => {
      document.execCommand('Delete');
      document.write("Test passes if it does not crash.");
    });
    document.execCommand('InsertLineBreak');
  };
</script>
<body>
  <a href="#">
    <b>
      <iframe></iframe>
      <input></input>
    </b>
  </a>
</body>