[hack] Refactor: Put naming.lenv behind an interface
[hack] Refactor: Put naming.lenv behind an interface

Summary:
No semantic changes. This makes it easier to see how the lenv is
getting used.

Reviewed By: alexchow

Differential Revision: D2909514

fb-gh-sync-id: 049a77a087fc9d4b47bf850ba9fb1e1f82d9650d

nmote/flow,nmote/flow,MichaelDeBoey/flow,jdelStrother/flow,JonathanUsername/flow,TiddoLangerak/flow,shiftcars/flow,jdelStrother/flow,shiftcars/flow,gabro/flow,jamesgpearce/flow,JonathanUsername/flow,jeffmo/flow,popham/flow,chenglou/flow,claudiopro/flow,samwgoldman/flow,jamesgpearce/flow,nmote/flow,mroch/flow,jgrund/flow,facebook/flow,MichaelDeBoey/flow,facebook/flow,fletcherw/flow,d14b3l/flow,jamesgpearce/flow,jdelStrother/flow,jgrund/flow,JonathanUsername/flow,mroch/flow,d14b3l/flow,graue/flow,gabelevi/flow,d14b3l/flow,chenglou/flow,shiftcars/flow,shiftcars/flow,jeffmo/flow,mroch/flow,mroch/flow,AgentME/flow,JonathanUsername/flow,chenglou/flow,jgrund/flow,AprilArcus/flow,cesarandreu/flow,ylu1317/flow,d14b3l/flow,ForbesLindesay/flow,nmote/flow,jeffmo/flow,facebook/flow,jamesgpearce/flow,mroch/flow,MichaelDeBoey/flow,ylu1317/flow,jamesgpearce/flow,ForbesLindesay/flow,gabro/flow,AgentME/flow,popham/flow,jgrund/flow,ForbesLindesay/flow,claudiopro/flow,JonathanUsername/flow,chenglou/flow,facebook/flow,samwgoldman/flow,jdelStrother/flow,AprilArcus/flow,ForbesLindesay/flow,JonathanUsername/flow,AgentME/flow,chenglou/flow,jdelStrother/flow,claudiopro/flow,gabelevi/flow,facebook/flow,claudiopro/flow,gabro/flow,fletcherw/flow,jgrund/flow,nmote/flow,MichaelDeBoey/flow,nmote/flow,popham/flow,popham/flow,graue/flow,gabelevi/flow,facebook/flow,ylu1317/flow,TiddoLangerak/flow,jeffmo/flow,AprilArcus/flow,chenglou/flow,fletcherw/flow,graue/flow,popham/flow,jamesgpearce/flow,TiddoLangerak/flow,AprilArcus/flow,graue/flow,gabelevi/flow,JonathanUsername/flow,MichaelDeBoey/flow,samwgoldman/flow,fletcherw/flow,gabelevi/flow,graue/flow,AprilArcus/flow,gabro/flow,gabelevi/flow,ForbesLindesay/flow,graue/flow,cesarandreu/flow,popham/flow,claudiopro/flow,samwgoldman/flow,popham/flow,TiddoLangerak/flow,d14b3l/flow,jeffmo/flow,ylu1317/flow,gabro/flow,jeffmo/flow,ylu1317/flow,gabelevi/flow,jamesgpearce/flow,jgrund/flow,samwgoldman/flow,shiftcars/flow,samwgoldman/flow,samwgoldman/flow,fletcherw/flow,cesarandreu/flow,cesarandreu/flow,facebook/flow,jdelStrother/flow,ForbesLindesay/flow,nmote/flow,mroch/flow,shiftcars/flow,mroch/flow,gabro/flow,TiddoLangerak/flow,fletcherw/flow,AprilArcus/flow,AgentME/flow,AgentME/flow,d14b3l/flow