add test for big cubic -- currently disabled

BUG=skia:

Change-Id: Ief11a1e54d427b1241b47f3cfab5b44fb656443a
Reviewed-on: https://skia-review.googlesource.com/7607
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed