Dedup root file list before looking up dependents or lazy-mode-focusing
Dedup root file list before looking up dependents or lazy-mode-focusing

Summary:
There's no sense looking up dependents or lazy-mode-focusing the same file
twice.

Reviewed By: panagosg7

Differential Revision: D7821978

fbshipit-source-id: c729c03693ab63a32ecf24fd3f3c066b93c2fe30

claudiopro/flow,samwgoldman/flow,nmote/flow,gabelevi/flow,popham/flow,AgentME/flow,facebook/flow,popham/flow,facebook/flow,popham/flow,JonathanUsername/flow,mroch/flow,jamesgpearce/flow,gabelevi/flow,AgentME/flow,nmote/flow,popham/flow,popham/flow,mroch/flow,samwgoldman/flow,jamesgpearce/flow,JonathanUsername/flow,JonathanUsername/flow,samwgoldman/flow,nmote/flow,JonathanUsername/flow,mroch/flow,mroch/flow,JonathanUsername/flow,jamesgpearce/flow,samwgoldman/flow,AgentME/flow,jamesgpearce/flow,popham/flow,gabelevi/flow,samwgoldman/flow,AgentME/flow,mroch/flow,nmote/flow,jamesgpearce/flow,nmote/flow,mroch/flow,jamesgpearce/flow,gabelevi/flow,claudiopro/flow,JonathanUsername/flow,facebook/flow,nmote/flow,samwgoldman/flow,gabelevi/flow,facebook/flow,claudiopro/flow,nmote/flow,gabelevi/flow,JonathanUsername/flow,gabelevi/flow,mroch/flow,facebook/flow,samwgoldman/flow,jamesgpearce/flow,AgentME/flow,facebook/flow,claudiopro/flow,popham/flow,claudiopro/flow,facebook/flow