Extract per-edge quad vertex tesselation code into reusable interface

This moves the vertex templates and the edge outset/tessellation code into a new GrPerEdgeAAQuadHelper h/cpp file. The vertex template hierarchy has been expanded to include an optional local coordinate type: void, SkPoint, or SkPoint3. The texture op only uses SkPoint for its local coordinates but the regular rect op will need void and SkPoint3 as well.

A large part of the added code is providing the tessellation specializations for those new local coordinate types.

Bug: skia:
Change-Id: Id8cf2a17342f30b299b16be95e341d4991951c38
Reviewed-on: https://skia-review.googlesource.com/c/164611
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
4 files changed