video-controls-layer-creation-squashing.html

<!DOCTYPE HTML>
<html>
<head>
<style>
    div {
        will-change:transform;
        position: absolute;
        top: 100px;
        left: 0px;
        width: 300px;
        height: 300px;
        background-color: green;
        z-index: 2;
    }
    video {
        position: absolute;
        top: 0px;
        left: 0px;
        width: 272px;
        height: 153px;
        z-index: 3;
    }
</style>
<script src="../../media/media-controls.js"></script>
</head>
<script>
function runTest() {
    if (window.testRunner) {
        testRunner.waitUntilDone();
        testRunner.dumpAsText();
    }

    var video = document.querySelector('video');
    enableTestMode(video);
    video.onerror = endTest;
    video.src = "bogus.ogv";
}

function endTest() {
    if (window.testRunner && window.internals) {
        testRunner.setCustomTextOutput(internals.layerTreeAsText(document));
        testRunner.notifyDone();
    }
}
</script>
<body onload="runTest()">
        <!-- video controls should appear in their own layer -->
        <video controls>
        </video>

        <!-- this div is beneath the video in a stacking context and should through the video into compositing due to overlap -->
        <div></div>
    </body>
</html>

chromium/third_party/blink/web_tests/compositing/video/video-controls-layer-creation-squashing.html