ba01fa5bc9
Summary: This diff introduces the `onDestroy` hook that can be used by plugins to listen to the event where a plugin is cleaned up (either because it is disabled, or because the client is being cleaned up) Reviewed By: jknoxville Differential Revision: D22208121 fbshipit-source-id: 9c4951ae671be611f21da171c548d4054c481166