Migrate AAConvexPathOp off of GrLegacyMeshDrawOp

Change-Id: If6df4292ec5c78a7f2fdde0a4540f7327e69e294
Reviewed-on: https://skia-review.googlesource.com/20058
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
3 files changed