always fit f=0

This helps keep curves sanely invertible.

Bug: chromium:880648

Change-Id: I6299faae53fead2801fba4156b2ffc09ce16da7b
Reviewed-on: https://skia-review.googlesource.com/c/167261
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
5 files changed