<!DOCTYPE html>
<html>
<head>
    <style>
    .box {
        position: absolute;
        z-index: 1;
        top: 20px;
        left: 30px;
        height: 400px;
        width: 400px;
        border: 20px solid green;
        transform: translate(0);
        transform-origin: top left;
        background-color: blue;
    }
    
    body.changed .box {
        transform: translate3d(0, 0, 0) scale(0.5, 0.5);
    }
    </style>
    <script>
        if (window.testRunner) {
            testRunner.dumpAsText();
            testRunner.waitUntilDone();
        }

        window.addEventListener('load', () => {
            setTimeout(() => {
                if (window.internals)
                    window.internals.startTrackingRepaints();

                document.body.classList.add('changed');

                if (window.internals)
                    document.getElementById('layers').textContent = window.internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_REPAINT_RECTS);

                if (window.testRunner)
                    testRunner.notifyDone();
            }, 0);
        }, false);
    </script>
</head>
<body>
    <div class="box"></div>
<pre id="layers"></pre>
</body>
</html>