Summary:
Fixes T8150. Small generalization:
- Timeline has a dropdown with no special logic; make that generic.
- Use it in Phriction.
Test Plan:
- Used Phriction dropdown on desktop and mobile.
- Used timeline dropdown.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T8150
Differential Revision: https://secure.phabricator.com/D12931
4622993885