Summary:
See facebook/yoga#483. We should not transfer the layout if the layout didn't change. (using ```hasNewLayout```). This also changes that the lock on the java node is only aquired if needed, and it holds the lock only for the time the values are set and not for the time all it's children are set.
Closes https://github.com/facebook/yoga/pull/484
Reviewed By: astreet
Differential Revision: D4802966
Pulled By: emilsjolander
fbshipit-source-id: e8a8f2280ad6b25b98fc68b07eac68e0ec80fe3e