R1:843414379529

Fix `AphrontTagView` visibility

Summary: Ref T6822.

Test Plan: `grep`

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T6822

Differential Revision: https://secure.phabricator.com/D11368