GrTessellator: collinear edges during sanitize.

When three collinear edges occur during the sanitize_contours() pass,
their vertices may not yet have been discovered to be coincident.  So
we must do the vertex comparison by point, rather than by pointer.

Bug: 860655
Change-Id: I89dc7526905bb5473206661348fee431371731a0
Reviewed-on: https://skia-review.googlesource.com/141523
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Stephen White <senorblanco@chromium.org>
2 files changed