check for too-big rects, as we do for paths

Bug: oss-fuzz:8334
Change-Id: Ibeeb8adfbfa543406da4b42aa742a6290bd65509
Reviewed-on: https://skia-review.googlesource.com/128541
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed