Rewrite GrRenderTargetContext::drawRegion antialias logic.

This will hopefully make a later change that refactors how aa is passed to GrRenderTargetContext a little easier to review.

Change-Id: Ie750d237714a0407ec1e5604c0daa080da32519b
Reviewed-on: https://skia-review.googlesource.com/5630
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed