GrTessellator AA: fix 1px wide paths.

Move 0 count check below the call to count outer polygons,
so we don't abort on a path with outer but no inner 
geometry.

This fixes the "thin_right_angle" and "thin_rect_and_triangle"
samples when running GM:thinconcavepaths --pr tess.

Change-Id: I9a75711787f729ce3a1d5313daa491098e397184
Reviewed-on: https://skia-review.googlesource.com/15661
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Stephen White <senorblanco@chromium.org>
1 file changed