Revert "transform paint color to dst colorspace"

This reverts commit 6eb36214461794626291a01c3150f7239e4a91a3.

Reason for revert: UBSAN/ASAN failures

Original change's description:
> transform paint color to dst colorspace
> 
> Hopefully I can start to knock off effects that need
> to be converted to dst colorspace one at a time now.
> 
> My rough list is,
>    - paint color               <----
>    - image shader
>    - sprite blitter
>    - gradients?
>    - mode color filter
>    - lighting color filter
>    - high contrast filter
>    - toSRGB color filter
> 
> This change cuts the diffs between 8888 and srgb from
> ~540 to ~500.
> 
> I left myself a note about not being able to interpret null
> to sRGB at a high level yet.  That'd cause a ton of 8888 diffs,
> and I think SkColorSpaceXformCanvas diffs too.
> 
> Change-Id: Id66a63e0e92130927f267719aeccb8bbcd92973a
> Reviewed-on: https://skia-review.googlesource.com/140244
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Mike Klein <mtklein@google.com>

TBR=mtklein@google.com,brianosman@google.com

Change-Id: I31a17b6e70916c463d38488703cfade347c05f2b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/140382
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

2 files changed, 4 insertions, 31 deletions

diff --git a/src/core/SkRasterPipeline.cpp b/src/core/SkRasterPipeline.cpp
index 5125476dde..46658969cd 100644
--- a/src/core/SkRasterPipeline.cpp
+++ b/src/core/SkRasterPipeline.cpp
@@ -90,7 +90,9 @@ void SkRasterPipeline::dump() const {
 #endif
 
 void SkRasterPipeline::append_constant_color(SkArenaAlloc* alloc, const float rgba[4]) {
-    // r,g,b might be outside [0,1], but alpha should probably always be in [0,1].
+    SkASSERT(0 <= rgba[0] && rgba[0] <= 1);
+    SkASSERT(0 <= rgba[1] && rgba[1] <= 1);
+    SkASSERT(0 <= rgba[2] && rgba[2] <= 1);
     SkASSERT(0 <= rgba[3] && rgba[3] <= 1);
 
     if (rgba[0] == 0 && rgba[1] == 0 && rgba[2] == 0 && rgba[3] == 1) {
@@ -104,10 +106,6 @@ void SkRasterPipeline::append_constant_color(SkArenaAlloc* alloc, const float rg
         Sk4f color = Sk4f::Load(rgba);
         color.store(&ctx->r);
 
-        // TODO: if any channel is out of [0,1], append a float-only stage
-        // that can handle that, instead of this uniform_color that assumes
-        // in-range values so it can work in lowp.
-
         // To make loads more direct, we store 8-bit values in 16-bit slots.
         color = color * 255.0f + 0.5f;
         ctx->rgba[0] = (uint16_t)color[0];
diff --git a/src/core/SkRasterPipelineBlitter.cpp b/src/core/SkRasterPipelineBlitter.cpp
index 3643637f0b..66a4a62734 100644
--- a/src/core/SkRasterPipelineBlitter.cpp
+++ b/src/core/SkRasterPipelineBlitter.cpp
@@ -12,7 +12,6 @@
 #include "SkColor.h"
 #include "SkColorFilter.h"
 #include "SkColorSpaceXformer.h"
-#include "SkColorSpaceXformSteps.h"
 #include "SkOpts.h"
 #include "SkPM4f.h"
 #include "SkPM4fPriv.h"
@@ -86,36 +85,12 @@ private:
     typedef SkBlitter INHERITED;
 };
 
-static SkPM4f premul_in_dst_colorspace(SkColor color, SkColorSpace* dstCS) {
-    float rgba[4];
-    swizzle_rb(SkNx_cast<float>(Sk4b::Load(&color)) * (1/255.0f)).store(rgba);
-
-    // SkColors are always sRGB.
-    auto srcCS = SkColorSpace::MakeSRGB().get();
-
-    // If dstCS is null, no color space transformation is needed (and apply() will just premul).
-    if (!dstCS) { dstCS = srcCS; }
-
-    SkColorSpaceXformSteps(srcCS, kUnpremul_SkAlphaType, dstCS)
-        .apply(rgba);
-
-    return {{rgba[0], rgba[1], rgba[2], rgba[3]}};
-}
-
 SkBlitter* SkCreateRasterPipelineBlitter(const SkPixmap& dst,
                                          const SkPaint& paint,
                                          const SkMatrix& ctm,
                                          SkArenaAlloc* alloc) {
-    // For legacy/SkColorSpaceXformCanvas to keep working,
-    // we need to sometimes still need to distinguish null dstCS from sRGB.
-#if 0
-    SkColorSpace* dstCS = dst.colorSpace() ? dst.colorSpace()
-                                           : SkColorSpace::MakeSRGB().get();
-#else
     SkColorSpace* dstCS = dst.colorSpace();
-#endif
-    SkPM4f paintColor = premul_in_dst_colorspace(paint.getColor(), dstCS);
-
+    SkPM4f paintColor = SkPM4f_from_SkColor(paint.getColor(), dstCS);
     auto shader = as_SB(paint.getShader());
 
     SkRasterPipeline_<256> shaderPipeline;