Add GrQuadUtils namespace to hold ResolveAAType function

Change-Id: I6357af83b55be8efa8dfd709acde908296c05f82
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/216605
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
7 files changed