chromium/third_party/blink/web_tests/transforms/transform-positioned-ancestor.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">

<html lang="en">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  <title>Transform and positioned ancestor</title>
  <style type="text/css" media="screen">
  
    #wrapper {
      border: 1px solid black;
      position: relative;
      width: 300px;
    }
    .container {
      height: 200px;
      width: 200px;
      margin: 50px;
      background-color: gray;
      transform: rotate(0);
    }
    .box {
      position: absolute;
      left: 50px;
      top: 50px;
      height: 100px;
      width: 100px;
      background-color: red;
    }
    
    .green-box {
      position: absolute;
      left: 100px;
      top: 100px;
      height: 100px;
      width: 100px;
      background-color: green;
    }

  </style>
</head>
<body>

<p>You should see a green box inside a gray box. If you see red, the test has failed. <a href="https://bugs.webkit.org/show_bug.cgi?id=18885">https://bugs.webkit.org/show_bug.cgi?id=18885</a>
</p>
<div id="wrapper">

  <div class="container">
    <div class="box"></div>
  </div>
  <div class="green-box"></div>
</div>

</body>
</html>