[SVG] SVGAnimatedRect migration to new SVG property impl.

Source/core/svg/SVGRect.idl

Index: Source/core/svg/SVGRect.idl
diff --git a/Source/core/svg/SVGRect.idl b/Source/core/svg/SVGRect.idl
index e148788295b608f6fe387ed948e89e5f58aeb981..3925a3a57031975bd0e75b0c7e765efb9beb6c9d 100644
--- a/Source/core/svg/SVGRect.idl
+++ b/Source/core/svg/SVGRect.idl
@@ -20,10 +20,13 @@
  * Boston, MA 02110-1301, USA.
  */
 
-interface SVGRect {
-    [StrictTypeChecking] attribute float x;
-    [StrictTypeChecking] attribute float y;
-    [StrictTypeChecking] attribute float width;
-    [StrictTypeChecking] attribute float height;
+[
+    ImplementedAs=SVGRectTearOff,
+    SetReference(SVGElement contextElement)
+] interface SVGRect {
+    [StrictTypeChecking, RaisesException=Setter] attribute float x;
+    [StrictTypeChecking, RaisesException=Setter] attribute float y;
+    [StrictTypeChecking, RaisesException=Setter] attribute float width;
+    [StrictTypeChecking, RaisesException=Setter] attribute float height;
 };