Fix division by zero in profiling
Fix division by zero in profiling

Summary: Derp.

Reviewed By: samwgoldman

Differential Revision: D5573907

fbshipit-source-id: 405815c4ef62b6f305ab943d4e0f99ae74f80c43

TiddoLangerak/flow,jamesgpearce/flow,nmote/flow,MichaelDeBoey/flow,facebook/flow,TiddoLangerak/flow,mroch/flow,mroch/flow,popham/flow,popham/flow,gabelevi/flow,nmote/flow,jamesgpearce/flow,claudiopro/flow,AgentME/flow,facebook/flow,samwgoldman/flow,claudiopro/flow,nmote/flow,JonathanUsername/flow,popham/flow,samwgoldman/flow,JonathanUsername/flow,TiddoLangerak/flow,jamesgpearce/flow,mroch/flow,MichaelDeBoey/flow,samwgoldman/flow,samwgoldman/flow,jamesgpearce/flow,ylu1317/flow,jamesgpearce/flow,popham/flow,MichaelDeBoey/flow,facebook/flow,ylu1317/flow,popham/flow,MichaelDeBoey/flow,gabelevi/flow,nmote/flow,MichaelDeBoey/flow,gabelevi/flow,JonathanUsername/flow,gabelevi/flow,mroch/flow,popham/flow,JonathanUsername/flow,samwgoldman/flow,samwgoldman/flow,mroch/flow,nmote/flow,jamesgpearce/flow,AgentME/flow,jamesgpearce/flow,JonathanUsername/flow,gabelevi/flow,nmote/flow,AgentME/flow,facebook/flow,JonathanUsername/flow,ylu1317/flow,popham/flow,facebook/flow,mroch/flow,AgentME/flow,claudiopro/flow,ylu1317/flow,JonathanUsername/flow,claudiopro/flow,ylu1317/flow,nmote/flow,gabelevi/flow,gabelevi/flow,samwgoldman/flow,TiddoLangerak/flow,facebook/flow,facebook/flow,claudiopro/flow,TiddoLangerak/flow,AgentME/flow,mroch/flow