[7.x] Migrate visualization controls to use references (#30880)#31294

Merged

mikecote merged 1 commit intoelastic:7.xfrom mikecote:backport/7.x/pr-30880

Feb 15, 2019

+218-26

Commits on Feb 15, 2019

Migrate visualization controls to use references (elastic#30880 )
mikecote
committed