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chromium/third_party/blink/web_tests/fast/forms/color-scheme/media/video-playback-speed-menu.html 

<!DOCTYPE html>
<script src="../../../../media/media-file.js"></script>
<script src="../../../../media/video-paint-test.js"></script>
<script src="../../../../media/media-controls.js"></script>
<script src="../../../../media/overflow-menu.js"></script>
<meta name="color-scheme" content="light dark">

<body style="padding-top: 200px; padding-left: 100px">
    <video controls></video>
    <script>
        var video = document.querySelector("video");
        enableTestMode(video);
        video.onloadeddata = function () {
            var overflowMenu = getOverflowMenuButton(video);
            var coords = elementCoordinates(overflowMenu);
            clickAtCoordinates(coords[0], coords[1]);

            // Navigate to the Playback Speed sub-menu
            eventSender.keyDown('ArrowUp');
            eventSender.keyDown('Enter');
        };
        setVideoSrcAndWaitForFirstFrame("../../../../media/content/test.ogv");
    </script>
</body>