Swap front and back stencil sides when rendering bottom-left

This makes sure the front face is always clockwise in device space,
and the back face is always counterclockwise, regardless of origin.

Bug: skia:
Change-Id: If4b9be6197e0fb9ac22a58f9198afd37a49a8187
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/208991
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
10 files changed