Bug 991812: Remove uses of RefCounted<T> that live in Gecko. r=ehsan
Bug 991812: Remove uses of AtomicRefCounted<T> that live in Gecko. r=ehsan
Bug 995405: Don't pass around references to the observer service off the main thread. r=michal
Bug 993734: Stop pretending that the observer service is threadsafe. r=bsmedberg
Bug 994971: Don't export nsObserverService.h. r=bsmedberg