Homestyx hydra

R1:9773dc0e6cc4

Add "X / Y Comments" button to Differential persistent header

Summary: Ref M1476.

Test Plan: {F4987991}

Reviewers: chad

Reviewed By: chad

Differential Revision: https://secure.phabricator.com/D18072
Repository: R1 hydra
Commit Date: Jun 5 2017