chromium/third_party/blink/web_tests/external/wpt/css/css-contain/contain-paint-clip-019.html

<!DOCTYPE html>

<meta charset="UTF-8">

<title>CSS Containment Test: 'contain: paint' and clipping prevents scrollbars</title>

<link rel="author" title="Vladimir Levin" href="mailto:[email protected]">
<link rel="help" href="https://www.w3.org/TR/css-contain-1/#containment-paint">
<link rel="match" href="reference/contain-paint-clip-019-ref.html">

<meta content="This test checks that the paint containment of an element clips contents.
  It should also prevent layout overflow from being propagated to ancestors." name="assert">

<style>
  #container {
    contain: paint;
    width: 100px;
    height: 100px;
  }
  #green {
    background-color: green;
    width: 100px;
    height: 100px;
  }
  #red {
    background-color: red;
    width: 100px;
    height: 10000px;
  }
</style>

<p>Test passes if there there is a green square. No red and no scrollbars should be visible.</p>

<div id="container">
  <div id="green"></div>
  <div id="red"></div>
</div>