Refactored SkColorSpace and added in a Lab PCS GM

dm/DMSrcSink.cpp

Index: dm/DMSrcSink.cpp
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index e777815baabce71bcf5ac20ad74e2721dd52eda2..f09e8ff47888b470b9a1e10c122796a8fe76d0de 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -11,7 +11,7 @@
 #include "SkCodec.h"
 #include "SkCodecImageGenerator.h"
 #include "SkColorSpace.h"
-#include "SkColorSpace_Base.h"
+#include "SkColorSpace_XYZTRC.h"
 #include "SkColorSpaceXform.h"
 #include "SkCommonFlags.h"
 #include "SkData.h"
@@ -920,7 +920,9 @@ Error ColorCodecSrc::draw(SkCanvas* canvas) const {
         decodeInfo = decodeInfo.makeAlphaType(kPremul_SkAlphaType);
     }
     if (kRGBA_F16_SkColorType == fColorType) {
-        decodeInfo = decodeInfo.makeColorSpace(as_CSB(decodeInfo.colorSpace())->makeLinearGamma());
+        SkASSERT(as_CSB(decodeInfo.colorSpace())->toXYZD50());
+        SkColorSpace_XYZTRC* csXYZ = static_cast<SkColorSpace_XYZTRC*>(decodeInfo.colorSpace());
+        decodeInfo = decodeInfo.makeColorSpace(csXYZ->makeLinearGamma());
     }
 
     SkImageInfo bitmapInfo = decodeInfo;