chromium/third_party/blink/web_tests/external/wpt/css/css-transforms/preserve3d-and-flattening-z-order-001.html

<!DOCTYPE HTML>
<meta charset="utf-8">
<title>CSS Test (Transforms): Flattening at the leafward edges of a preserve-3d scene</title>
<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1255544">
<link rel="author" title="L. David Baron" href="https://dbaron.org/">
<link rel="author" title="Google" href="http://www.google.com/">
<link rel="help" href="http://www.w3.org/TR/css-transforms-2/#3d-transform-rendering">
<meta name="assert" content="Elements are drawn in the correct z-order.">
<link rel="match" href="reference/green.html">

<style>
div {
  position: absolute;
  height: 100px;
  width: 100px;
  top: 0;
  left: 0;
  background: red;
}
.outer {
  position: relative;
}
.outer, .sibling {
  transform-style: preserve-3d;
}
</style>

<p>Pass if there is NO red below:</p>

<div class="outer">
  <div class="sibling"></div>
  <div class="flattener"><div class="child"></div></div>
  <div class="sibling" style="background: green"></div>
</div>