R1:21651c6bc6aa

Fix highlighting anchors on hashchange

Summary: Listener sends the event to `try_anchor` in the first argument.

Test Plan: Displayed diff, clicked on `#comment-1`, went back in history, clicked on `#summary`.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D3327