Introduce GrColorSpaceXform, for gamut conversion on textures

src/effects/SkBlurMaskFilter.cpp

Index: src/effects/SkBlurMaskFilter.cpp
diff --git a/src/effects/SkBlurMaskFilter.cpp b/src/effects/SkBlurMaskFilter.cpp
index 6a20d48c758cd1f64f5fe4ab38d2fca93bece2be..b7893c50b48d080fc23d8726e8fa362157571dfb 100644
--- a/src/effects/SkBlurMaskFilter.cpp
+++ b/src/effects/SkBlurMaskFilter.cpp
@@ -1260,7 +1260,7 @@ bool SkBlurMaskFilterImpl::filterMaskGPU(GrTexture* src,
         SkMatrix matrix;
         matrix.setIDiv(src->width(), src->height());
         // Blend pathTexture over blurTexture.
-        paint.addCoverageFragmentProcessor(GrSimpleTextureEffect::Make(src, matrix));
+        paint.addCoverageFragmentProcessor(GrSimpleTextureEffect::Make(src, nullptr, matrix));
         if (kInner_SkBlurStyle == fBlurStyle) {
             // inner:  dst = dst * src
             paint.setCoverageSetOpXPFactory(SkRegion::kIntersect_Op);