chromium/third_party/blink/web_tests/external/wpt/css/css-contain/content-visibility/content-visibility-074-ref.html

<!doctype HTML>
<html>
<meta charset="utf8">
<title>CSS Content Visibility: toggling auto with composited descedant (reference)</title>
<link rel="author" title="Vladimir Levin" href="mailto:[email protected]">
<link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility">

<style>
#a { will-change: transform; }
#b { height: 15000px; }
#c {
  width: 800px;
  height: 600px;
}
#d {
  will-change: transform;
  top: 0px;
  width: 500px;
  height: 500px;
  background: green;
}
.contain {
  contain: layout style paint;
}

</style>

<div id="a">
</div>
<div id="b">
  <div id="c" class=contain>
    <div id="d"></div>
    </div>
  </div>
</div>