chromium/third_party/blink/web_tests/paint/invalidation/compositing/invalidations-on-composited-layers.html

<!DOCTYPE html>

<!--
This test checks that repaint testing works with composited layers.
-->

<html>
<head>
  <style type="text/css">
    #parent {
        will-change: transform;
        width: 400px;
        height: 400px;
        background: blue;
    }

    #child {
        will-change: transform;
        position: relative;
        left: 50px;
        top: 50px;
        width: 75px;
        height: 75px;
        background: green;
    }

  </style>
  <script src="../resources/text-based-repaint.js"></script>
  <script>
      function repaintTest() {
          var parent = document.getElementById('parent');
          var child = document.getElementById('child');

          child.style.background = 'blue';
          parent.style.background = 'green';
      }

      runRepaintAndPixelTest();
  </script>
</head>
<body>
  <div id="parent">
    <div id="child"></div>
  </div>
</body>
</html>