Better composition in FRPGalleryViewController.
Better composition in FRPGalleryViewController.

SilenceZhou/FunctionalReactivePixels,hbucius/FunctionalReactivePixels,jspahrsummers/FunctionalReactivePixels,RiuHDuo/FunctionalReactivePixels,sandyway/FunctionalReactivePixels,fxd/FunctionalReactivePixels,LiuShulong/FunctionalReactivePixels,ManagerOrganization/FunctionalReactivePixels,ashfurrow/FunctionalReactivePixels