Add writeToMemory() API to SkColorSpace

include/core/SkColorSpace.h

Index: include/core/SkColorSpace.h
diff --git a/include/core/SkColorSpace.h b/include/core/SkColorSpace.h
index 57f74e985d9a732b0d6416046cb13ed1b003249f..f0547984b53594c75e99509fb248d8dcfbd5355a 100644
--- a/include/core/SkColorSpace.h
+++ b/include/core/SkColorSpace.h
@@ -83,6 +83,12 @@ public:
      */
     sk_sp<SkData> serialize() const;
 
+    /**
+     *  If |memory| is nullptr, returns the size required to serialize.
+     *  Otherwise, serializes into |memory| and returns the size.
+     */
+    size_t writeToMemory(void* memory) const;
+
     static sk_sp<SkColorSpace> Deserialize(const void* data, size_t length);
 
 protected: