Remove SK_SUPPORT_LEGACY_EVAL_CUBIC-guarded code

To land after http://crrev.com/2610923004.

R=caryclark@google.com

Change-Id: I0a748801be06530f98009e977e816c90f1ef5934
Reviewed-on: https://skia-review.googlesource.com/6611
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
1 file changed