How to persist fullscreen mode in browser like youtube.com playlist does?

[jeremies]

In youtube.com, when you play a playlist in fullscreen mode, the fullscreen persists when switching from one video to another in the playlist. I am trying to do the same in my website, where there is a playlist of videos, and user can watch in fullscreen mode, but a new video starts to play, the fullscreen doesn't persist.

I understand from Fullscreen API, there needs a user interaction to make the video fullscreen. But, then how the heck youtube.com is doing it?

Any help would be appreciated! Thanks.