GrTessellator: yet another out-of-range splitting fix.

It's actually possible for an intersection to be out-of-range on both
the intersected edges (e.g., below both bottom points), because
floating point. So we need to clamp against both edges.

Bug: 846014
Change-Id: I9fe25a1fcd3b5242af7b1ee36b17f1e968aeb836
Reviewed-on: https://skia-review.googlesource.com/132323
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Stephen White <senorblanco@chromium.org>
2 files changed