SDK / exoplayer

Now you can do cool things (if you really want to!) like
play a video twice, then play a second video, then loop
the whole thing, all seamlessly.

new LoopingMediaSource(
  new LoopingMediaSource(firstVideoSource, 2),
  secondVideoSource));

You can also just loop, which is probably more useful :).

Issue: #490

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132049599