only check for deferred descendants in __DEV__ mode
only check for deferred descendants in __DEV__ mode

Summary:
We should not be calling `hasDeferredDescendant` at all if we're in production
mode if the network layer doesn't actually support defer since it adds overhead.

Reviewed By: josephsavona

Differential Revision: D2726059

fb-gh-sync-id: b858c444dd527c79860cc4c120459ca6d62f8166

atxwebs/relay,josephsavona/relay,iamchenxin/relay,andimarek/generic-relay,cpojer/relay,cesarandreu/relay,freiksenet/relay,venepe/relay,apalm/relay,michaelchum/relay,voideanvalue/relay,venepe/relay,josephsavona/relay,NevilleS/relay,freiksenet/relay,xuorig/relay,NevilleS/relay,Aweary/relay,michaelchum/relay,yungsters/relay,kassens/relay,chirag04/relay,iamchenxin/relay,kassens/relay,gabelevi/relay,venepe/relay,zpao/relay,xuorig/relay,kassens/relay,Aweary/relay,gabelevi/relay,xuorig/relay,yungsters/relay,kassens/relay,atxwebs/relay,zpao/relay,gabelevi/relay,facebook/relay,chentsulin/relay,voideanvalue/relay,freiksenet/relay,cesarandreu/relay,atxwebs/relay,rosskevin/relay,andimarek/generic-relay,wincent/relay,heracek/relay,heracek/relay,josephsavona/relay,voideanvalue/relay,xuorig/relay,wincent/relay,facebook/relay,voideanvalue/relay,chentsulin/relay,benjaminogles/relay,rosskevin/relay,zpao/relay,wincent/relay,wincent/relay,voideanvalue/relay,dbslone/relay,iamchenxin/relay,facebook/relay,heracek/relay,apalm/relay,NevilleS/relay,yungsters/relay,cpojer/relay,cpojer/relay,cesarandreu/relay,mroch/relay,kassens/relay,apalm/relay,mroch/relay,wincent/relay,benjaminogles/relay,dbslone/relay,chirag04/relay,facebook/relay,iamchenxin/relay,xuorig/relay,michaelchum/relay,xuorig/relay,mroch/relay,Aweary/relay,forter/generic-relay,benjaminogles/relay,cpojer/relay,atxwebs/relay,voideanvalue/relay,kassens/relay,andimarek/generic-relay,facebook/relay,chentsulin/relay,wincent/relay,chirag04/relay,facebook/relay