Limit iterations when computing convex inset.

In the worst case we should compare each vertex in the polygon
to the others just once, so we should have at worst n^2 iterations.

Bug: skia:8079
Change-Id: Ic22064e86d6eb08d9165b2feb5050701ec8e9639
Reviewed-on: https://skia-review.googlesource.com/135865
Auto-Submit: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
1 file changed