Summary:
Implementing the consensus approach from the comments on
this PR:
https://github.com/facebook/react-native/pull/486
We use a boolean flag in the Obj-C code to determine whether
to animate or not, and then provide two public JS functions
that call the Obj-C with or without the flag.
Closes https://github.com/facebook/react-native/pull/509
Github Author: Charlie Cheever <ccheever@gmail.com>
Test Plan: Imported from GitHub, without a `Test Plan:` line.