<html>
    <head>
        <script>
            function playVideo() {
                document.getElementById("video").play().then(function() {
                    try {
                        window.webkit.messageHandlers.testHandler.postMessage("autoplayed");
                    } catch(e) { }
                }).catch(function() {
                    try {
                        window.webkit.messageHandlers.testHandler.postMessage("did-not-play");
                    } catch(e) { }
                });
            }

            function pauseVideo() {
                document.getElementById("video").pause();
            }

            function videoDidPause() {
                try {
                    window.webkit.messageHandlers.testHandler.postMessage("on-pause");
                } catch(e) { }
            }
        </script>
    </head>
    <body onload="playVideo()">
        <video id="video" onpause=videoDidPause() playsinline src="test.mp4" />
    </body>
</html>