Summary:
the flush + optimized multiGet result in an obscure bug that results when two multiGet requests with overlapping key sets get issued. The result array for both requests ends up bigger than the key array (because it has duplicates)
Closes https://github.com/facebook/react-native/pull/5514
Reviewed By: svcscm
Differential Revision: D2908264
Pulled By: nicklockwood
fb-gh-sync-id: 60be1bce4acfc47083e4ae28bb8b63f9dfa56039
52755fdde2