chromium/third_party/blink/web_tests/external/wpt/css/css-display/display-first-line-002.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>Display flex first line with floated first letter</title>
<link rel="help" href="https://crbug.com/1097595">
<link rel="match" href="display-first-line-002-ref.html">
<style id="styleElm">
  #victim::first-line { display:flex;  }
  #victim::first-letter { float:right; }
</style>

<!-- The contenteditable DIV is just here to trigger legacy layout
     fallback, and a DCHECK failure identical to the one in the bug
     report. If we remove it, we'll get NG layout, and then it will
     actually DCHECK-fail inside NG inline layout code instead. -->
<div contenteditable></div>

<p>The word "PASS" should be seen below. There should be no DCHECK
  failure.</p>
<div id="child" style="display:none;"></div>
<div id="victim" style="width:fit-content;">
  SPAS
</div>
<script>
  document.body.offsetTop;
  styleElm.appendChild(child);
  document.body.offsetTop;
  victim.style.color = "blue";
</script>