Gradients are serialized (and can be constructed) as SkColor4f + SkColorSpace

src/effects/gradients/SkLinearGradient.cpp

Index: src/effects/gradients/SkLinearGradient.cpp
diff --git a/src/effects/gradients/SkLinearGradient.cpp b/src/effects/gradients/SkLinearGradient.cpp
index 4bf5e3cc207d14b6363be495f3dda90784675c87..3372499a636cd507033a513d617ca804a969485f 100644
--- a/src/effects/gradients/SkLinearGradient.cpp
+++ b/src/effects/gradients/SkLinearGradient.cpp
@@ -63,8 +63,9 @@ sk_sp<SkFlattenable> SkLinearGradient::CreateProc(SkReadBuffer& buffer) {
     SkPoint pts[2];
     pts[0] = buffer.readPoint();
     pts[1] = buffer.readPoint();
-    return SkGradientShader::MakeLinear(pts, desc.fColors, desc.fPos, desc.fCount, desc.fTileMode,
-                                        desc.fGradFlags, desc.fLocalMatrix);
+    return SkGradientShader::MakeLinear(pts, desc.fColors, std::move(desc.fColorSpace), desc.fPos,
+                                        desc.fCount, desc.fTileMode, desc.fGradFlags,
+                                        desc.fLocalMatrix);
 }
 
 void SkLinearGradient::flatten(SkWriteBuffer& buffer) const {