[SVG] SVGLength{,List} migration to new SVG property impl.

Source/core/svg/SVGSVGElement.h

Index: Source/core/svg/SVGSVGElement.h
diff --git a/Source/core/svg/SVGSVGElement.h b/Source/core/svg/SVGSVGElement.h
index 65f8c69c30ee74e4db43591f4d6ffa60021a5c97..adaebc7dd86074d4fca82db8f3f3317beb0029b1 100644
--- a/Source/core/svg/SVGSVGElement.h
+++ b/Source/core/svg/SVGSVGElement.h
@@ -28,6 +28,7 @@
 #include "core/svg/SVGExternalResourcesRequired.h"
 #include "core/svg/SVGFitToViewBox.h"
 #include "core/svg/SVGGraphicsElement.h"
+#include "core/svg/SVGLengthTearOff.h"
 #include "core/svg/SVGZoomAndPan.h"
 #include "wtf/WeakPtr.h"
 
@@ -111,7 +112,7 @@ public:
     void deselectAll();
 
     static float createSVGNumber();
-    static SVGLength createSVGLength();
+    static PassRefPtr<SVGLengthTearOff> createSVGLength();
     static SVGAngle createSVGAngle();
     static SVGPoint createSVGPoint();
     static SVGMatrix createSVGMatrix();
@@ -133,6 +134,11 @@ public:
 
     bool hasEmptyViewBox() const { return viewBoxCurrentValue().isValid() && viewBoxCurrentValue().isEmpty(); }
 
+    SVGAnimatedLength* x() const { return m_x.get(); }
+    SVGAnimatedLength* y() const { return m_y.get(); }
+    SVGAnimatedLength* width() const { return m_width.get(); }
+    SVGAnimatedLength* height() const { return m_height.get(); }
+
 private:
     explicit SVGSVGElement(Document&);
     virtual ~SVGSVGElement();
@@ -160,11 +166,11 @@ private:
 
     PassRefPtr<NodeList> collectIntersectionOrEnclosureList(const SVGRect&, SVGElement*, CollectIntersectionOrEnclosure) const;
 
+    RefPtr<SVGAnimatedLength> m_x;
+    RefPtr<SVGAnimatedLength> m_y;
+    RefPtr<SVGAnimatedLength> m_width;
+    RefPtr<SVGAnimatedLength> m_height;
     BEGIN_DECLARE_ANIMATED_PROPERTIES(SVGSVGElement)
-        DECLARE_ANIMATED_LENGTH(X, x)
-        DECLARE_ANIMATED_LENGTH(Y, y)
-        DECLARE_ANIMATED_LENGTH(Width, width)
-        DECLARE_ANIMATED_LENGTH(Height, height)
         DECLARE_ANIMATED_BOOLEAN(ExternalResourcesRequired, externalResourcesRequired)
         DECLARE_ANIMATED_RECT(ViewBox, viewBox)
         DECLARE_ANIMATED_PRESERVEASPECTRATIO(PreserveAspectRatio, preserveAspectRatio)