
Passing in a Provider<CurrentUser> into PermissionBackend is boiler-platy. This change adds a convenience method to PermissionBackend and DefaultPermissionBackend to limit this boiler-plate. Future commits will remove #user(Provider<CurrentUser>) from PermissionBackend, once all callers were moved. Change-Id: Ifcd07fe2c7d2673a66b2b4f9eff06ee8a3b6b943