<!DOCTYPE html>

<html>
<head>
    <style>
        body {
            height: 1000px;
            background-image: repeating-linear-gradient(to bottom, silver, white 100px);
        }

        .fixed {
            position: fixed;
            left: 10px;
            width: 600px;
            top: 10px;
            height: 100px;
            background-color: gray;
        }
    </style>
    <script>
        function doScroll()
        {
            window.setTimeout(function() {
                document.scrollingElement.scrollTop = 120;
                window.parent.frameDidChange();
            }, 0);
        }
        window.addEventListener('load', doScroll, false);
    </script>
</head>
<body>

<div class="fixed">
    Top bar
</div>

</body>
</html>