Make GrTextureOp capable of edge antialiasing.

Bug: skia:
Change-Id: I0088bdbb6a76811611fa4628656bf9513c5bf04a
Reviewed-on: https://skia-review.googlesource.com/91105
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
7 files changed