Second small fragment from "Reduce dependence on GrSurface's origin field"

TBR=bsalomon@google.com
Change-Id: Ifcfe56b1117b64821b2bfc34ba36d120227d15fa
Reviewed-on: https://skia-review.googlesource.com/25802
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
19 files changed