SkColorSpace: remove named API, add gamut API

BUG=skia:

Change-Id: I01c5e1874c9a034febc64e25b3aaafb5050393a6
Reviewed-on: https://skia-review.googlesource.com/8021
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>
diff --git a/src/codec/SkGifCodec.cpp b/src/codec/SkGifCodec.cpp
index af0e8bc..2903717 100644
--- a/src/codec/SkGifCodec.cpp
+++ b/src/codec/SkGifCodec.cpp
@@ -106,7 +106,7 @@
 
     const auto imageInfo = SkImageInfo::Make(reader->screenWidth(), reader->screenHeight(),
                                              colorType, alphaType,
-                                             SkColorSpace::MakeNamed(SkColorSpace::kSRGB_Named));
+                                             SkColorSpace::MakeSRGB());
     return new SkGifCodec(encodedInfo, imageInfo, reader.release());
 }