The new Flow is much stricter about promiseAll. It's relaxed a bit in Flow 0.214, but for now we have to comply with the additional strictness.
I separated out this diff because it required some minimal changes to thread-permission-updates.js in order to rename and export a type. This way the context for those changes is more clear.
Depends on D9786
These props aren't used. Shouldn't this give a warning?