<!DOCTYPE html> <!-- webkit-test-runner [ internal:AsyncOverflowScrollingEnabled=true ] -->
<html>
<head>
    <style>
        #scroller {
            margin: 50px;
            height: 512px;
            width: 400px;
            overflow-y: scroll;
            border: 1px solid black;
        }
        
        .contents {
			height: 3000px;
            background-image: repeating-linear-gradient(white, silver 400px);
        }

    </style>
    <script>
        if (window.testRunner) {
            testRunner.dumpAsText();
            testRunner.waitUntilDone();
        }
		
		function startTest()
		{
			requestAnimationFrame(() => {
				scroller.scrollTop = 20;

				requestAnimationFrame(() => {
					scroller.scrollTop = 200;

		            document.getElementById('layers').innerText = internals.layerTreeAsText(document,
		                internals.LAYER_TREE_INCLUDES_VISIBLE_RECTS | internals.LAYER_TREE_INCLUDES_TILE_CACHES);
					
					if (window.testRunner)
						testRunner.notifyDone();
				});
			});
		}

        window.addEventListener('load', startTest, false);
    </script>
</head>
<body>

    <div id="scroller">
        <div class="contents">
        </div>
    </div>

<pre id="layers">Layer tree goes here</p>
</body>
</html>