Don't make promises about rowbytes

Since we just rely on SkBitmap to manage rowbytes, we don't need to
separately track it in the surface.

Bug: 1038304
Change-Id: Iea2d486019bf4c5bf4f2a87eabc5f00ad71949fc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/266219
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
2 files changed