R1:da892bde7c6e

Go to correct position after revealing comments

Test Plan:
Go to revision with lots of comments in Firefox.
Click on one of the last three comments permalink.
Repeat in Chrome.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, epriestley

Differential Revision: https://secure.phabricator.com/D1702