Cleanup GPU gamut transformation code

src/image/SkImageShader.cpp

Index: src/image/SkImageShader.cpp
diff --git a/src/image/SkImageShader.cpp b/src/image/SkImageShader.cpp
index 9afd2073602fba7113436e14273fbfd226f6f4bd..e52deff270d48775ed6918697b0e2bff6e2130f2 100644
--- a/src/image/SkImageShader.cpp
+++ b/src/image/SkImageShader.cpp
@@ -216,8 +216,7 @@ sk_sp<GrFragmentProcessor> SkImageShader::asFragmentProcessor(const AsFPArgs& ar
 
     SkImageInfo info = as_IB(fImage)->onImageInfo();
     sk_sp<GrColorSpaceXform> colorSpaceXform = GrColorSpaceXform::Make(info.colorSpace(),
-                                                                       args.fDstColorSpace,
-                                                                       info.alphaType());
+                                                                       args.fDstColorSpace);
     sk_sp<GrFragmentProcessor> inner;
     if (doBicubic) {
         inner = GrBicubicEffect::Make(texture, std::move(colorSpaceXform), matrix, tm);