When triangles get too thin it's possible for FP round-off error to
actually give us the wrong winding direction, causing rendering
artifacts. This change also allows us to unblacklist ANGLE.
Bug: skia:7805
Bug: skia:7820
Change-Id: Ibaa0f033eba625d720e3a594c4515d8264cc413d
Reviewed-on: https://skia-review.googlesource.com/123262
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
