fix round_asymmetric_to_int to also bias bottom and right

BUG=skia:6294

Change-Id: I1ee1031f1fb7cb035916e8945ce5396759955885
Reviewed-on: https://skia-review.googlesource.com/9700
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Cary Clark <caryclark@google.com>
1 file changed