chromium/third_party/blink/web_tests/external/wpt/html/the-xhtml-syntax/parsing-xhtml-documents/adopt-while-parsing-001.html

<!doctype html>
<title>Appending from the parser after adopting in an XML document doesn't miss notifications</title>
<link rel="match" href="adopt-while-parsing-001-ref.html">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1511329">
<link rel="author" title="Emilio Cobos Álvarez" href="mailto:[email protected]">
<link rel="author" title="Mozilla" href="https://mozilla.org">
<style>
  html, body { margin: 0 }
</style>
<script>
  // If we don't get notified of the <div> insertion, the PASS text will never appear.
  function parsingInterrupted() {
    let frameDoc = document.querySelector("iframe").contentDocument;
    let root = frameDoc.documentElement;
    document.documentElement.appendChild(root);
    root.offsetTop;
  }
</script>
<iframe src="adopt-while-parsing.xhtml"></iframe>