<!DOCTYPE HTML>
<html>
<head>
    <script src="../resources/js-test-pre.js"></script>
</head>
<body>
    <script>
        var currentFrame = 0;
        var failed = false;

        function finishTest()
        {
            if (failed)
                testFailed("Some of the requestAnimationFrame() callback timestamps were larger than Performance.now() by more than 3ms.");
            else
                testPassed("All the differences between requestAnimationFrame() callback timestamps and Performance.now() were within 3ms.")
            finishJSTest();
        }
        
        function doAnimation(timestamp)
        {
            const Tolerance = 3;
            const WarmupFrames = 5;

            var performanceNow = window.performance.now();
            if (++currentFrame > WarmupFrames && Math.abs(timestamp - performanceNow) >= Tolerance) {
                debug("requestAnimationFrame() timestamp = " + timestamp + ", window.performance.now() = " + performanceNow);
                failed = true;
            }

            const MaxFrames = 25;
            if (currentFrame == MaxFrames)
                finishTest();
            else
                requestAnimationFrame(doAnimation);
        }
        
        window.jsTestIsAsync = true;
        requestAnimationFrame(doAnimation);
    </script>
    <script src="../resources/js-test-post.js"></script>
</body>
</html>