Move supplemental transform to rare data

Source/core/svg/SVGGraphicsElement.h

Index: Source/core/svg/SVGGraphicsElement.h
diff --git a/Source/core/svg/SVGGraphicsElement.h b/Source/core/svg/SVGGraphicsElement.h
index 325e2bf0c1591c91c42dcb4dbe6da9611bbd6b8e..810882fe7f0e9ea38470a2c655f58f613701f539 100644
--- a/Source/core/svg/SVGGraphicsElement.h
+++ b/Source/core/svg/SVGGraphicsElement.h
@@ -52,7 +52,7 @@ public:
 
     virtual AffineTransform localCoordinateSpaceTransform(SVGElement::CTMScope) const override { return animatedLocalTransform(); }
     virtual AffineTransform animatedLocalTransform() const;
-    virtual AffineTransform* supplementalTransform() override;
+    virtual AffineTransform* animateMotionTransform() override;
 
     virtual FloatRect getBBox();
     PassRefPtr<SVGRectTearOff> getBBoxFromJavascript();
@@ -82,9 +82,6 @@ protected:
 
 private:
     virtual bool isSVGGraphicsElement() const override final { return true; }
-
-    // Used by <animateMotion>
-    OwnPtr<AffineTransform> m_supplementalTransform;
 };
 
 inline bool isSVGGraphicsElement(const SVGElement& element)