Summary:
public
This exposes a proper API for adding synchronous callbacks to JS, as an optional feature of the executor.
This is based on nicklockwood's work in D2764492, but avoids refactoring bridge/executor interactions for the time being, since we agree on this API and can move the actual callsites around later.
Reviewed By: nicklockwood
Differential Revision: D2799506
fb-gh-sync-id: af209d9a0be927f3404205feb16e59745cc37aec