Performs inset and outset operations on simple polygons and returns
a simple polygon, if possible.
Bug: skia:
Change-Id: I6d468174ad70b5279b736c532e19cbb84ff9f955
Reviewed-on: https://skia-review.googlesource.com/116483
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
