shadow-dom-mozilla-1066554-ref.html

<!DOCTYPE html>
<html>
<meta charset="utf-8">
<title>Test for Mozilla bug 1066554 - Shadow DOM loads MathML stylesheets as needed</title>
<body>
  <math>
    <msup>
      <mi>X</mi>
      <mi>X</mi>
    </msup>
  </math>
</body>
</html>

chromium/third_party/blink/web_tests/external/wpt/mathml/relations/html5-tree/shadow-dom-mozilla-1066554-ref.html