SkRasterPipeline shader adapter

(lifted from https://skia-review.googlesource.com/c/7088/)

R=mtklein@google.com,herb@google.com,reed@google.com

CQ_INCLUDE_TRYBOTS=skia.primary:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD

Change-Id: Idddb84069423c5fc535bea0a65a5b21a4d07084d
Reviewed-on: https://skia-review.googlesource.com/7615
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Reed <reed@google.com>
4 files changed