handle divide by zero in paint

Bug: oss-fuzz:7003
Change-Id: Ie3266292ca94a28cc7023ed5255895d25f0d4dc8
Reviewed-on: https://skia-review.googlesource.com/115041
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
1 file changed