Change cubicmap to eval directly (no table)

- gives us zero setup cost
- perfect accuracy (at least better than our 16-polyline approx)
- slower at runtime, but for skottie seems still way under the radar

Bug: skia:
Change-Id: Ic01f76184c359c65d6af9a3bedeac34a2ad7d3a6
Reviewed-on: https://skia-review.googlesource.com/146961
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
4 files changed