<!DOCTYPE html> <!-- webkit-test-runner [ internal:AsyncOverflowScrollingEnabled=true ] --><html>
<html>
<head>
    <style>
        #scroller {
            width: 400px;
            height: 400px;
            margin: 20px;
            overflow: scroll;
            will-change: z-index;
            border: 1px solid black;
        }
        .contents {
            height: 300%;
        }
        
        .rating {
            position: relative;
            background-color: green;
            padding: 10px;
        }
        
        .wrapper {
            left: 100px;
            top: 100px;
            background-color: rgba(128, 128, 128, 0.2)
        }
        
        .behind {
            position: absolute;
            top: 160px;
            width: 50px;
            height: 50px;
            background-color: silver;
        }
        
        .composited {
            transform: translateZ(0);
        }
        
        .filler {
            height: 200px;
        }
    </style>
    <script>
        if (window.testRunner) {
            testRunner.dumpAsText();
            testRunner.waitUntilDone();
        }
        window.addEventListener('load', () => {
            setTimeout(() => {
                window.internals.startTrackingRepaints();
                document.getElementById('scroller').scrollTop = 80;
                document.getElementById('layers').textContent = window.internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_REPAINT_RECTS);
                testRunner.notifyDone();
            }, 50);
        }, false);
    </script>
</head>
<body>
    <div id="scroller">
            <div class="composited behind"></div>
        <div class="contents">
            <div class="filler"></div>
            <div class="rating">&nbsp;</div>
            <div class="filler"></div>
        </div>
    </div>
<pre id="layers"></pre>
</body>
</html>