Revert "Retry "SkRasterPipelineBlitter: support A8"..."

This reverts commit f55ea6a1deb21120944d406124a2984b5009260a.

Reason for revert: crbug.com/679147

Original change's description:
> Retry "SkRasterPipelineBlitter: support A8"...
> 
>     ...preferring SkA8_Coverage_Blitter over SkRasterPipelineBlitter.
> 
> I think we could make this work with SkRasterPipelineBlitter (tell it, draw white in Src mode with this mask), but the existing blitter is pretty hard to beat in efficiency and correctness.
> 
> CQ_INCLUDE_TRYBOTS=skia.primary:Perf-Ubuntu-Clang-GCE-CPU-AVX2-x86_64-Debug-MSAN,Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD
> 
> 
> Change-Id: I72df9995c63f3334d8111c59711818cb5ed1e63c
> Reviewed-on: https://skia-review.googlesource.com/6627
> Reviewed-by: Mike Klein <mtklein@chromium.org>
> Commit-Queue: Mike Klein <mtklein@chromium.org>
> 

TBR=mtklein@chromium.org,brianosman@google.com,reed@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I6a36b4c087a52e54f4d591ded40e6a202fb77068
Reviewed-on: https://skia-review.googlesource.com/6760
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>

1 files changed, 0 insertions, 10 deletions

diff --git a/src/opts/SkRasterPipeline_opts.h b/src/opts/SkRasterPipeline_opts.h
index 3fe43e9838..143a9ece79 100644
--- a/src/opts/SkRasterPipeline_opts.h
+++ b/src/opts/SkRasterPipeline_opts.h
@@ -497,16 +497,6 @@ STAGE_CTX(lerp_565, const uint16_t**) {
     a = 1.0f;
 }
 
-STAGE_CTX(load_a8, const uint8_t**) {
-    auto ptr = *ctx + x;
-    r = g = b = 0.0f;
-    a = SkNf_from_byte(load(tail, ptr));
-}
-STAGE_CTX(store_a8, uint8_t**) {
-    auto ptr = *ctx + x;
-    store(tail, SkNx_cast<uint8_t>(SkNf_round(255.0f, a)), ptr);
-}
-
 STAGE_CTX(load_565, const uint16_t**) {
     auto ptr = *ctx + x;
     from_565(load(tail, ptr), &r,&g,&b);