SIGN IN SIGN UP

Add semantics for Sliders (#4808)

Also, make SemanticsOwner into a real class and use it instead of a static in
several places.
A
Adam Barth committed
5ed8f1a1fdf50192dab6be49904c8c56389e84d1
Parent: f0671ed
Committed by GitHub <noreply@github.com> on 7/1/2016, 8:38:24 PM