Summary: As per discussion in #2423 - possible fix for crash. (cc: @javache)
Please share feedback regarding the PR, we are going to be using this diff in production to see if it fixes the crashes we are seeing.
(fixes#2423)
Closes https://github.com/facebook/react-native/pull/2494
Reviewed By: @javache
Differential Revision: D2433515
Pulled By: @nicklockwood