Summary: We need a way for different apps to inject dependencies or additional functionality into Fabric - ReactNativeConfig might be a special case, but I think this could clean up it's integration nicely, and I'm using this for a uitemplate cache system so we can use CompactDisk or other storage systems for caching depending on the app.
Reviewed By: mdvacca
Differential Revision: D13407287
fbshipit-source-id: 45481908434e6235850aa4d2d6b2bfb936a23be7
089dba3842