Summary:
This is the JS side of D23010844 (https://github.com/facebook/react-native/commit/73242b45a9f7f9ecce8f5124ac3d1665f575be74).
In the past I tried a few heuristics to guess when a batch of Animated Operations were ready, and none of these were super reliable. But it turns out we can safely allow JS to manage that explicitly.
Non-Fabric still uses the old behavior which seems fine.
Changelog: [Internal]
Reviewed By: mdvacca
Differential Revision: D23010937
fbshipit-source-id: 4a513672c166ceaa8b6daa387e46a2a95b60ce53