SkColorSpace: remove named API, add gamut API

Reland from: https://skia-review.googlesource.com/c/8021/

BUG=skia:

Change-Id: I18985f130587b15fccbc86b76b2bb5c49ba5ba8a
Reviewed-on: https://skia-review.googlesource.com/8136
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>
diff --git a/src/gpu/SkGr.cpp b/src/gpu/SkGr.cpp
index ad43eef..0dbe577 100644
--- a/src/gpu/SkGr.cpp
+++ b/src/gpu/SkGr.cpp
@@ -303,7 +303,7 @@
 
 GrColor4f SkColorToUnpremulGrColor4f(SkColor c, SkColorSpace* dstColorSpace) {
     if (dstColorSpace) {
-        auto srgbColorSpace = SkColorSpace::MakeNamed(SkColorSpace::kSRGB_Named);
+        auto srgbColorSpace = SkColorSpace::MakeSRGB();
         auto gamutXform = GrColorSpaceXform::Make(srgbColorSpace.get(), dstColorSpace);
         return SkColorToUnpremulGrColor4f(c, true, gamutXform.get());
     } else {