layer-repaint.html | Explore in Territory

<!DOCTYPE html>

<html>
<head>
  <style type="text/css" media="screen">
    .container {
        border: 1px solid black;
        height: 300px;
        width: 200px;
        transform: translateZ(0);
    }
    
    #tester {
        margin: 50px;
        height: 100px;
        width: 100px;
        background-color: red;
    }
  </style>
  <script type="text/javascript" charset="utf-8">
    function doTest() {
        setTimeout("changeBackground();", 10);
    }
    function changeBackground() {
        document.getElementById('tester').style.backgroundColor = 'green';
        if (window.testRunner)
            testRunner.notifyDone();
    }
    if (window.testRunner)
        testRunner.waitUntilDone();
    window.addEventListener('load', doTest, false);
  </script>
</head>
<body>
    <p>Test for repaint in a composited layer. You should see no red below.</p>
  <div class="container">
    <div id="tester"></div>
  </div>
</body>
</html>

chromium/third_party/blink/web_tests/paint/invalidation/compositing/layer-repaint.html