Reland "Revert "Revert "Make FP optimizations helpers use SkAlphaType not GrColorType"""

This is a reland of 997b37fdb986b45ff9941319b0111b188e749cfc

Layout tests have been suppressed.

Original change's description:
> Revert "Revert "Make FP optimizations helpers use SkAlphaType not GrColorType""
>
> This reverts commit 078e8faa26d8b1f33a92e57f587be011150d1776.
>
> Change-Id: I67b2970584db5a1afbf9928b77c5444947ef71a3
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/255897
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>

Change-Id: I6db4cff8b71ef1f29ac47f7729b9514d009f730a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/256225
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrSoftwarePathRenderer.cpp b/src/gpu/GrSoftwarePathRenderer.cpp
index 4245e9e..e4ae6c0 100644
--- a/src/gpu/GrSoftwarePathRenderer.cpp
+++ b/src/gpu/GrSoftwarePathRenderer.cpp
@@ -144,7 +144,6 @@
 
 void GrSoftwarePathRenderer::DrawToTargetWithShapeMask(
         sk_sp<GrTextureProxy> proxy,
-        GrColorType srcColorType,
         GrRenderTargetContext* renderTargetContext,
         GrPaint&& paint,
         const GrUserStencilSettings& userStencilSettings,
@@ -166,7 +165,7 @@
                                               SkIntToScalar(-textureOriginInDeviceSpace.fY));
     maskMatrix.preConcat(viewMatrix);
     paint.addCoverageFragmentProcessor(GrSimpleTextureEffect::Make(
-            std::move(proxy), srcColorType, maskMatrix, GrSamplerState::Filter::kNearest));
+            std::move(proxy), kPremul_SkAlphaType, maskMatrix, GrSamplerState::Filter::kNearest));
     DrawNonAARect(renderTargetContext, std::move(paint), userStencilSettings, clip, SkMatrix::I(),
                   dstRect, invert);
 }
@@ -386,10 +385,9 @@
                           *args.fUserStencilSettings, *args.fClip, *args.fViewMatrix, devClipBounds,
                           unclippedDevShapeBounds);
     }
-    DrawToTargetWithShapeMask(
-            std::move(proxy), GrColorType::kAlpha_8, args.fRenderTargetContext,
-            std::move(args.fPaint), *args.fUserStencilSettings, *args.fClip, *args.fViewMatrix,
-            SkIPoint{boundsForMask->fLeft, boundsForMask->fTop}, *boundsForMask);
+    DrawToTargetWithShapeMask(std::move(proxy), args.fRenderTargetContext, std::move(args.fPaint),
+                              *args.fUserStencilSettings, *args.fClip, *args.fViewMatrix,
+                              SkIPoint{boundsForMask->fLeft, boundsForMask->fTop}, *boundsForMask);
 
     return true;
 }