R1:8813c7be0e39

Use assert_instances_of() everywhere but Differential and Diffusion

Summary: NOTE: This is not produced by a script so there might be errors. Please review carefully.

Test Plan: Browse around.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran

Differential Revision: https://secure.phabricator.com/D2091