one more empty contour

Add one more empty contour check.

R=kjlubick@google.com
BUG=skia:6073

Change-Id: Ie971875d37388f6bd86a0bdaeaf9230d64aca38d
Reviewed-on: https://skia-review.googlesource.com/6356
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Cary Clark <caryclark@google.com>
1 file changed