R1:cc1def6ceaab

Remove some array typehints for passing around

Summary: See discussion at https://secure.phabricator.com/D19492#241996

Test Plan: Refreshed a few Diffusion tabs; nothing broke.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D19578