Revert "[skif] Take advantage of PixelBoundary in rescale()"

This reverts commit ac454b80130cdf90a74b36b067a2284ce12375fa.

Reason for revert: Blocking Android roll + red bots

Original change's description:
> [skif] Take advantage of PixelBoundary in rescale()
>
> Change-Id: Ie6d5b43f0a74035e9f4e785330931e856905a25c
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/816517
> Reviewed-by: Robert Phillips <robertphillips@google.com>
> Commit-Queue: Michael Ludwig <michaelludwig@google.com>

Change-Id: I8714217d96db2a3e0f4a906a1d6949fc1130722d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/859120
Auto-Submit: Robert Phillips <robertphillips@google.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
3 files changed