[skottie] Anti-alias masks

TBR=

Change-Id: I16eca80b515fde8ad87a79c01ffd0ea2b3e31259
Reviewed-on: https://skia-review.googlesource.com/101740
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
1 file changed