chromium/third_party/blink/web_tests/fast/frames/frameset-bordercolor-inheritance.html

<!DOCTYPE html>
<html class="reftest-wait">
<script>
window.onload = () => {
  requestAnimationFrame(() => requestAnimationFrame(() => {
    document.body.removeAttribute('bordercolor');
    document.documentElement.removeAttribute('class');
  }));
};
</script>
<frameset bordercolor="red" border="100" rows="50%,*">
  <frameset cols="50%,*"><frame></frame><frame></frame></frameset>
  <frame></frame>
</frameset>
</html>