chromium/third_party/blink/web_tests/external/wpt/css/css-contain/contain-paint-026.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Containment Test: Paint containment and box-shadow</title>
<link rel="help" href="https://drafts.csswg.org/css-contain-1/#containment-paint">
<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
<meta name=assert content="Paint containment should clip box-shadow effect on child.">
<style>
#contain-paint {
  contain: paint;
  width: 100px;
  height: 100px;
  background: red;
}

#child {
  background: green;
  box-shadow: 0 0 100px 100px red;
  width: 100px;
  height: 100px;
}
</style>
<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
<div id="contain-paint">
  <div id="child"></div>
</div>