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/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index 88b1963..3b849c1 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -1014,7 +1014,7 @@
 
     sk_sp<SkColorSpace> dstSpace = nullptr;
     if (kDst_sRGB_Mode == fMode) {
-        dstSpace = SkColorSpace::MakeNamed(SkColorSpace::kSRGB_Named);
+        dstSpace = SkColorSpace::MakeSRGB();
     } else if (kDst_HPZR30w_Mode == fMode) {
         dstSpace = SkColorSpace::MakeICC(dstData->data(), dstData->size());
     }