chromium/third_party/blink/web_tests/external/wpt/css/css-scoping/host-has-001.html

<!doctype html>
<meta charset="utf-8">
<title>:host(:has(...)) direct descendent</title>
<link rel="help" href="https://drafts.csswg.org/css-scoping/#host-selector">
<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 id="host">
    <template shadowrootmode="open">
      <style>
        div {
          width: 100px;
          height: 100px;
          background-color: red;
        }
        :host(:has(section)) div {
          background-color: green;
        }
      </style>
      <div></div>
      <slot></slot>
    </template>
    <section></section>
</div>