Introduce GrColorSpaceXform, for gamut conversion on textures

src/gpu/effects/GrConfigConversionEffect.cpp

Index: src/gpu/effects/GrConfigConversionEffect.cpp
diff --git a/src/gpu/effects/GrConfigConversionEffect.cpp b/src/gpu/effects/GrConfigConversionEffect.cpp
index d2fde96bb3b85eb79faffe9a9049ea4b3b659f84..ed532768db3da5b7857e3829ef2d1f0983444256 100644
--- a/src/gpu/effects/GrConfigConversionEffect.cpp
+++ b/src/gpu/effects/GrConfigConversionEffect.cpp
@@ -98,7 +98,7 @@ GrConfigConversionEffect::GrConfigConversionEffect(GrTexture* texture,
                                                    const GrSwizzle& swizzle,
                                                    PMConversion pmConversion,
                                                    const SkMatrix& matrix)
-    : INHERITED(texture, matrix)
+    : INHERITED(texture, nullptr, matrix)
     , fSwizzle(swizzle)
     , fPMConversion(pmConversion) {
     this->initClassID<GrConfigConversionEffect>();
@@ -296,7 +296,7 @@ sk_sp<GrFragmentProcessor> GrConfigConversionEffect::Make(GrTexture* texture,
         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
         // then we may pollute our texture cache with redundant shaders. So in the case that no
         // conversions were requested we instead return a GrSimpleTextureEffect.
-        return GrSimpleTextureEffect::Make(texture, matrix);
+        return GrSimpleTextureEffect::Make(texture, nullptr, matrix);
     } else {
         if (kRGBA_8888_GrPixelConfig != texture->config() &&
             kBGRA_8888_GrPixelConfig != texture->config() &&