chromium/third_party/blink/web_tests/external/wpt/css/css-contain/content-visibility/content-visibility-004.html

<!doctype HTML>
<html>
<meta charset="utf8">
<title>CSS Content Visibility: hidden container in an iframe</title>
<link rel="author" title="Vladimir Levin" href="mailto:[email protected]">
<link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility">
<link rel="match" href="content-visibility-004-ref.html">
<meta name="assert" content="content-visibility hidden makes iframe contents hidden">

<p>Test passes if the word “Fail” does not appear in the box below.</p>

<iframe id="frame" srcdoc='
  <style>
  #container {
    width: 100px;
    height: 100px;
    content-visibility: hidden;
  }
  </style>
  <div id="container">Fail</div>
'></iframe>
</html>