Add support for SkCanvas::kStrict_SrcRectConstraint to GrTextureOp.

Change-Id: I8faa2838b3110b8080ac48bbe223240e3fb22998
Reviewed-on: https://skia-review.googlesource.com/129762
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
7 files changed