add a bulk shader path through SkRasterPipelineBlitter

Change-Id: I76f1f0c29b3408bffb7732ee1afb8337c478605e
Reviewed-on: https://skia-review.googlesource.com/17768
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Reviewed-by: Herb Derby <herb@google.com>
2 files changed