fix fuzz

corrupted intersection point lists
can loop forever. Add a safety
hatch to abort after a large number
of iterations.

TBR=kjlubick@google.com
BUG=700679

Change-Id: Ifd4b180b47ba3bbde38ade0bb13b16b8d645c1cb
Reviewed-on: https://skia-review.googlesource.com/9967
Reviewed-by: Cary Clark <caryclark@skia.org>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Cary Clark <caryclark@google.com>
5 files changed