Summary: It's possible for user code to be run in the ObserverManager thread outside of the refresh call (e.g. from Core destructor), so we can't rely on inManagerThread check to guarantee that Dependency recorder is active.

Reviewed By: yfeldblum

Differential Revision: D17805252

fbshipit-source-id: 5a858be0cf204da1342dc182e25797fd130c0458