<!DOCTYPE HTML>
<html>
<head>
    <script src="../resources/js-test-pre.js"></script>
    <style>
        #box {
            width: 100px;
            height: 100px;
            background-color: silver;
        }
        
        #box.animating {
            animation: spinner 0.25s steps(2) 1;
        }

        @keyframes spinner {
            from { transform: rotate(0deg); }
            to   { transform: rotate(360deg); }
        }
    </style>
    <script>
        window.jsTestIsAsync = true;

        let count = 0;
        window.addEventListener('load', () => {
            let box = document.getElementById('box');
            box.addEventListener('animationstart', () => {
                if (window.internals)
                    internals.startTrackingCompositingUpdates();
                shouldBe('count', '0');
            }, false);
            box.addEventListener('animationend', () => {
                if (window.internals)
                    count = internals.compositingUpdateCount();
                shouldBeTrue('count < 6');
                finishJSTest();
            }, false);
            
            box.classList.add('animating');
        }, false);
    </script>
</head>
<body>
    <div id="box"></div>
    <div id="console"></div>
    <script src="../resources/js-test-post.js"></script>
</body>
</html>