Always use raster pipeline for SkTwoPointConicalGradient

Change-Id: I14fc27c5ba8d6fd58df193a172148b7f5aca20bf
Reviewed-on: https://skia-review.googlesource.com/21262
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
3 files changed