Convert NonAALatticeOp to non-legacy GrMeshDrawOp.

Also adds a test factory and fixes a bug in the lattice iter validator where it compared each div value against the start rather than the previous div.

Bug: skia:
Change-Id: I30e9ddfcbaab7829a2f646ad851f99d1e518ab4a
Reviewed-on: https://skia-review.googlesource.com/21871
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
5 files changed