            function attachWithPreloadTest(preload)
            {
                async_test(function(test)
                {
                    var video = document.createElement("video");
                    var mediaSource = new MediaSource();
                    var mediaSourceURL = URL.createObjectURL(mediaSource);

                    video.preload = preload;
                    document.body.appendChild(video);
                    test.add_cleanup(function() {
                        document.body.r