Implemented by the contract id @mozilla.org/inter-app-communication-service;1
This interface contains helpers for Inter-App Communication API [1] related
purposes. A singleton service of this interface will be instantiated during
the system boot-up, which plays the role of the central service receiving
messages from and interacting with the content processes.
[1] https://wiki.mozilla.org/WebAPI/Inter_App_Communication_Alt_proposal