chromium/third_party/blink/web_tests/external/wpt/css/css-contain/contain-content-003.html

<!DOCTYPE html>

  <meta charset="UTF-8">

  <title>CSS Containment Test: element with 'contain: content' and absolutely positioned descendants</title>

  <link rel="author" title="GĂ©rard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
  <link rel="help" href="https://drafts.csswg.org/css-contain/#contain-property">
  <link rel="match" href="../reference/ref-filled-green-100px-square.xht">

  <meta name="assert" content="This test checks that an element with 'contain: content' acts as containing block for its absolutely positioned descendants.">

  <style>
  div
    {
      width: 100px;
    }

  div#contain-content
    {
      background-color: red;
      contain: content;
      height: 100px;
    }

  div.abspos
    {
      background-color: green;
      height: 50px;
      position: absolute;
      right: 0;
    }

  div#first-abspos
    {
      top: 0px;
    }

  div#second-abspos
    {
      bottom: 0px;
    }
  </style>

  <body>

  <p>Test passes if there is a filled green square and <strong>no red</strong>.

  <div id="contain-content">
    <div id="first-abspos" class="abspos"></div>
    <div id="second-abspos" class="abspos"></div>
  </div>