Replace GrAAType with flags for path renderers

Replaces the single GrAAType with a set of flags indicating which AA
types are acceptable for the path renderer to use.

Bug: skia:
Change-Id: I773565c904a360355e771966b6cddba697e1165f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/200840
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
22 files changed