R1:9777a1b4d1f5

Revisionss -> revision

Summary: Looks like a typo

Test Plan: Careful inspection.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D10540