position-fixed-transform-clipping.html

<!DOCTYPE>

<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  <title>Position fixed with transform clipping</title>

  <style type="text/css" media="screen">
    body {
      height: 2000px;
      margin: 0;
    }
    .container {
      position: fixed;
      width: 400px;
      height: 50px;
      border: 2px solid black;
      overflow: hidden;
    }

    .box {
      width: 100%;
      height: 100%;
      background-color: green;
      transform: translate(0, 0);
    }
    p {
      position: absolute;
      top: 100px;
    }
  </style>
  <script type="text/javascript" charset="utf-8">
    window.addEventListener('load', function() {
      window.scrollBy(0, 25);
    }, false);
  </script>
</head>
<body>
  
  <p><a href="https://bugs.webkit.org/show_bug.cgi?id=29346">https://bugs.webkit.org/show_bug.cgi?id=29346</a><br>
    Green box should fill the black border.</p>
  <div class="container">
    <div class="box">
    </div>
  </div>

</body>
</html>

chromium/third_party/blink/web_tests/fast/overflow/position-fixed-transform-clipping.html