Add a couple useful SVG constructors.

client/html/generated/src/wrapping/_SVGElementWrappingImplementation.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// WARNING: Do not edit - generated code.
-
-class SVGElementWrappingImplementation extends ElementWrappingImplementation implements SVGElement {
-  SVGElementWrappingImplementation._wrap(ptr) : super._wrap(ptr) {}
-
-  String get id() { return _ptr.id; }
-
-  void set id(String value) { _ptr.id = value; }
-
-  SVGSVGElement get ownerSVGElement() { return LevelDom.wrapSVGSVGElement(_ptr.ownerSVGElement); }
-
-  SVGElement get viewportElement() { return LevelDom.wrapSVGElement(_ptr.viewportElement); }
-
-  String get xmlbase() { return _ptr.xmlbase; }
-
-  void set xmlbase(String value) { _ptr.xmlbase = value; }
-}