chromium/third_party/blink/web_tests/external/wpt/css/selectors/featureless-003.html

<!doctype html>
<meta charset="utf-8">
<title>Selector lists match if any child selector does</title>
<link rel="help" href="https://drafts.csswg.org/selectors-4/#featureless">
<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
<p>Test passes if there is a filled green square.</p>
<div class=host>
    <template shadowrootmode="open">
      <style>
        div {
          width: 100px;
          height: 25px;
        }
        .red { background-color: red; }
        .green { background-color: green; }

        :host .t1, .error {
          background-color: green;
        }
        div:host .t2,
        :host .t2 {
          background-color: green;
        }

        div:host .t3,
        *:host .t3 {
          background-color: red;
        }
        /* no t4 test needed, just leaving the element in
          to prevent careful rounding from being necessary. */
      </style>
      <div class="red t1"></div>
      <div class="red t2"></div>
      <div class="green t3"></div>
      <div class="green t4"></div>
      <slot></slot>
    </template>
    <section></section>
</div>