Simplify decal for gradients

Previous change extended the stored array of colors/positions, and lost the
information that the intent was decal. This variant just uses custom stages
already developed for imageshader, keeping the intent of decal.

Bug: skia:7638
Change-Id: Ie3f30b42f4c1793487f08039cd3cea8e31aafc40
Reviewed-on: https://skia-review.googlesource.com/108280
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed