R1:6575cc568dab

Quicksand - fix spooky back button issue

Summary: Fixes T7911.

Test Plan:
- load a page
- click something else
- go back to original page via clicking
- browser refresh
- click something else
- browser back -- and it now works!

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7911

Differential Revision: https://secure.phabricator.com/D12603