<!DOCTYPE html>
<html>
<head>
    <style>
        body {
            margin: 0;
            background: silver;
            zoom: 1.25;
        }
        iframe {
            position: absolute;
            top: 50px;
            width: 200px;
            height: 200px;
            overflow: auto;
        }
    </style>
</head>
<body>
    <iframe src="about:blank"></iframe>
    <script>
        if (window.testRunner)
            testRunner.waitUntilDone();

        function testScrollRepaint()
        {
            var frame = window.frames[0];
            frame.onscroll = function() {
                if (window.testRunner)
                    testRunner.notifyDone();
            };
            frame.scrollBy(-90, -90);
        }
        onload = () => {
            var frame = window.frames[0];
            var doc = frame.document;
            doc.body.style.backgroundColor = 'white';
            doc.body.style.width = '2000px';
            doc.body.style.height = '2000px';
            doc.body.appendChild(doc.createTextNode('scroll me'));
            frame.scrollBy(100, 100);

            if (window.testRunner) {
                testRunner.displayAndTrackRepaints();
                testScrollRepaint();
            } else {
                setTimeout(testScrollRepaint, 100);
            }
        }
    </script>
</body>
</html>
