<!DOCTYPE html>
<html>
<head>
    <title>Test scrolling with composited content that has already been painted</title>
    <style>
        body {
            width: 600px;
        }
        div {
            -webkit-transform: translateZ(0);
            width: 1000px;
            height: 800px;
        }
    </style>
</head>
<body>
    <p>Test for <a href="https://bugs.webkit.org/show_bug.cgi?id=52720">Bug 52720 - REGRESSION
    (r75987): Assertion failure in WebView::scrollBackingStore when scrolling page with composited
    content</a>. The test passes if it doesn't assert in Debug builds.</p>

    <div></div>

    <script>
        onload = async () => {
            testRunner?.dumpAsText();
            testRunner?.waitUntilDone();
            // Force a paint so that the content will be painted at the current scroll offset (0x0)
            // before we scroll.
            await testRunner?.displayAndTrackRepaints();
            
            window.scrollBy(300, 0);
            testRunner?.notifyDone();
        }
    </script>
</body>
</html>