GrTessellator: fix for points which become non-finite on AA stroking.

If input points are near-infinite, they may become inf or NaN when
stroked.  Before converting the results of intersection from double
to float, clamp them to the [-FLT_MAX/FLT_MAX] range.

BUG=798679

Change-Id: I7d61130dd26147a9b7cfd38aa96567e3867b5c3e
Reviewed-on: https://skia-review.googlesource.com/90983
Commit-Queue: Stephen White <senorblanco@chromium.org>
Reviewed-by: Brian Osman <brianosman@google.com>
2 files changed