As far as I can gather, Media Source Extensions are supposed to be implemented in the latest current version of Chrome for Android. On the Chromium Dashboard there's also an indication that this should be working. However it seems that in practice it does not work (or at least does not work using the same API's used in Chrome for desktop).
I cannot seem to get it to work, and specifically, running this example on an Android phone (Samsung Galaxy S4) with KitKat and latest version of Chrome for Android results in a blank (black) video - it looks like the webm file is playing (if I replace the source with a webm file with sound I can hear the audio), however no video is showing.
Does this mean MSE is actually not supported yet on Chrome for Android? Is there any example someone knows of that suggests that it should in fact work?