Check sanitized data when fuzzing PolyUtils.

PolyUtils is only ever used when generating shadows, and the data there
is pre-clamped to 1/16th values, so we should be fuzzing on that.

Bug: oss-fuzz:39746
Change-Id: I609059ab14cd83f0dab2d40cb17e3cb7979cff8a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/493039
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
2 files changed