align prepareForMaskDrawing to agree for remote and gpu

The prepareForMaskDrawing in the RemoteStrike and the SkScalerCache
must fully agree on the maximum dimensions calculations.

Bug: chromium:1280180

Change-Id: Idfe98618027e5b04a481fa55f27e10b5bb048aea
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/494580
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
2 files changed