[SVGDom] Linear gradient 'spreadMethod' support

experimental/svg/model/SkSVGTypes.h

Index: experimental/svg/model/SkSVGTypes.h
diff --git a/experimental/svg/model/SkSVGTypes.h b/experimental/svg/model/SkSVGTypes.h
index b2343a15e4ea996b49879c89b0775f329efddb27..b07f9a2c8cba6ef6fd94fb2bbe9cf2fd5e17f162 100644
--- a/experimental/svg/model/SkSVGTypes.h
+++ b/experimental/svg/model/SkSVGTypes.h
@@ -167,4 +167,28 @@ private:
     Type fType;
 };
 
+class SkSVGSpreadMethod {
+public:
+    // These values must match Skia's SkShader::TileMode enum.
+    enum class Type {
+        kPad,       // kClamp_TileMode
+        kRepeat,    // kRepeat_TileMode
+        kReflect,   // kMirror_TileMode
+    };
+
+    constexpr SkSVGSpreadMethod() : fType(Type::kPad) {}
+    constexpr explicit SkSVGSpreadMethod(Type t) : fType(t) {}
+
+    SkSVGSpreadMethod(const SkSVGSpreadMethod&)            = default;
+    SkSVGSpreadMethod& operator=(const SkSVGSpreadMethod&) = default;
+
+    bool operator==(const SkSVGSpreadMethod& other) const { return fType == other.fType; }
+    bool operator!=(const SkSVGSpreadMethod& other) const { return !(*this == other); }
+
+    Type type() const { return fType; }
+
+private:
+    Type fType;
+};
+
 #endif // SkSVGTypes_DEFINED