This object just contained a pointer to the surface and dm,
and had one utility method.
Move the method to mw.editcheck, and pass around a surface model
or document model to other methods as appropriate.
Change-Id: Ie81d76dea2823b633328f982ee20027808bfc8e3
This was accidentally removed in d69d366469 during its refactor.
Because of the change to how checks are decided to be shown, I've made
AddReferenceEditCheck always be required -- later code in
hasAddedContentNeedingReference assumes that it's loaded anyway, so a
wiki deciding to configure it to not load at all for some account types
would have broken saving.
Bug: T373692
Change-Id: I007cd705451581ebacfa12e8ac5502bd1bc56a38
