Summary:
This is what I wanted to have the functional component for. This makes it super easy to keep track of the sections we've loaded and then make a side-effecting logging call "on mount" to keep track of the impressions different sidebar extensions get.
This should also save some CPU cycles when calculating what to show in the sidebar. Not sure how meaningful that is, though.
Reviewed By: jknoxville
Differential Revision: D19331682
fbshipit-source-id: 44f83006634f50d8f7437286b8915b63f9c47d40