Use __CLASS__ instead of hardcoding class names

Summary: Use __CLASS__ instead of hardcoding class names. Depends on D12804.

Test Plan: Eyeball it.

Reviewers: Blessed Reviewers, epriestley

Reviewed By: Blessed Reviewers, epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D12805