Introduce GrColorSpaceXform, for gamut conversion on textures

src/image/SkImageShader.cpp

Index: src/image/SkImageShader.cpp
diff --git a/src/image/SkImageShader.cpp b/src/image/SkImageShader.cpp
index 33edfdeb578849fc6b9490562511e3391be89b94..77639b21c74587bd051d2c949baa164a13fef62a 100644
--- a/src/image/SkImageShader.cpp
+++ b/src/image/SkImageShader.cpp
@@ -122,9 +122,9 @@ sk_sp<GrFragmentProcessor> SkImageShader::asFragmentProcessor(
 
     sk_sp<GrFragmentProcessor> inner;
     if (doBicubic) {
-        inner = GrBicubicEffect::Make(texture, matrix, tm);
+        inner = GrBicubicEffect::Make(texture, nullptr, matrix, tm);
     } else {
-        inner = GrSimpleTextureEffect::Make(texture, matrix, params);
+        inner = GrSimpleTextureEffect::Make(texture, nullptr, matrix, params);
     }
 
     if (GrPixelConfigIsAlphaOnly(texture->config())) {