R1:a07a06ab0895

Give custom controls passable disabled states

Summary: Fixes T9871. Ref T10004. These won't win any awards but it fixes them being incredibly weird and confusing.

Test Plan:
{F1029090}

- Tried to use controls, got reasonable behavior.
- Used normal controls to make sure I didn't break anything.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9871, T10004

Differential Revision: https://secure.phabricator.com/D14814