<!DOCTYPE html> <!-- webkit-test-runner [ AsyncOverflowScrollingEnabled=true ] -->
<head>
    <style>
        .scroller {
            position: relative;
            height: 300px;
            width: 300px;
            margin: 20px;
            border: 1px solid black;
            background-color: red;
            overflow-y: scroll;
        }
        .content {
            background-color: white;
        }
        .filler {
            width: 10px;
            height: 1000px;
        }
        .negative {
            position: relative;
            width: 100px;
            height: 100px;
            z-index: -1;
            background-color: gray;
        }
    </style>
</head>
<body>
<div class="scroller">
    <div class="content">
        <div class="negative"></div>
        <div class="filler"></div>
    </div>
</div>
</body>
</html>