<!DOCTYPE html> <!-- webkit-test-runner [ useFlexibleViewport=true EventHandlerDrivenSmoothKeyboardScrollingEnabled=true ] -->

<html>

<head>
    <script src="../../resources/ui-helper.js"></script>
    <script src="../../resources/js-test-pre.js"></script>
    <meta name="viewport" content="initial-scale=1.5, user-scalable=no">
    <script>
        if (window.testRunner) {
            testRunner.dumpAsText();
            testRunner.waitUntilDone();
        }
        
        function checkSuccessfulScroll(scrollObj)
        {
            if (window.scrollY <= scrollObj.offset) {
                debug("Unsuccessful Scroll - offset does not increase with each scroll event.");
                testRunner.notifyDone();
            }
            
            scrollObj.offset = window.scrollY;
            scrollObj.count++;
            
            if (scrollObj.count == 2) {
                debug("Successful Scroll");
                testRunner.notifyDone();
            }
        }
        
        async function runTest()
        {
            if (!window.testRunner || !testRunner.runUIScript)
                return;
                
            let scrollObj = {
                count: 0,
                offset: 0
            }
            
            document.addEventListener("scroll", function () {
                checkSuccessfulScroll(scrollObj);
            });
            
            await UIHelper.keyDown("pageDown");
        }
    </script>
    <style>
    #placeholder {
        width: 100px;
        height: 5000px;
    }
    </style>
</head>

<body style="margin: 0;" onload="runTest()">
    <div id="placeholder">
    <div id="console"></div>
    <script src="../../../resources/js-test-post.js"></script>
</body>

</html>