chromium/third_party/blink/web_tests/fast/clip/007.html

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">
<html>
<head>
<style>
div {
  width: 100px;
  height: 100px;
}

.green {
  background-color: green;
}

.red {
  background-color: red;
}

.overflow {
  overflow: hidden;
}

.positioned {
  position: absolute;
}

.fixed {
  position: fixed;
  left: 100px;
  top: 100px;
}

.offset {
  left: 100px;
  top: 100px;
}
</style>
<body>
You should see a 100x100 green square below.  If you see nothing at all or see any red, the test
has failed.  This test is checking to make sure overflow is done using 
a containing block model, and that a fixed positioned element inside an absolute positioned
element is not considered overflow.

<div class="overflow positioned">
  <div class="fixed">
    <div class="offset green positioned"></div>
  </div>
</div>