Summary:Everything wrapped in `<Incremental>` is rendered sequentially via `InteractionManager`.
The `onDone` callback is called when all descendent incremental components have
finished rendering, used by `<IncrementalPresenter>` to make the story visible all at once
instead of the parts popping in randomly.
This includes an example that demonstrates streaming rendering and the use of
`<IncrementalPresenter>`. Pressing down pauses rendering and you can see the
`TouchableOpacity` animation runs smoothly. Video:
https://youtu.be/4UNf4-8orQ4
Ideally this will be baked into React Core at some point, but according to jordwalke that's
going to require a major refactoring and take a long time, so going with this for now.
Reviewed By: ericvicenti
Differential Revision: D2506522
fb-gh-sync-id: 5969bf248de10d38b0ac22f34d7d49bf1b3ac4b6
shipit-source-id: 5969bf248de10d38b0ac22f34d7d49bf1b3ac4b6