Summary:
Opening this in a separate PR but the discussion can be viewed on #4832.
Basically, this is a native implementation and is a bit more elegant. The consensus on my previous PR was that it should be done natively rather than in JS.
There's now no maximum valid timeout value and a timeout of 0 will never time out.
ontimeout isn't implemented (yet) in this PR.
cc nicklockwood ide philikon
Closes https://github.com/facebook/react-native/pull/5038
Reviewed By: svcscm
Differential Revision: D2838743
Pulled By: nicklockwood
fb-gh-sync-id: 774f864ac35082bf522f7665f4311bd3affbe82c
1303e6d039