Use 'field' syntax in dart:dom interfaces.

client/dom/generated/src/interface/SVGMaskElement.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.
 
 interface SVGMaskElement extends SVGElement, SVGTests, SVGLangSpace, SVGExternalResourcesRequired, SVGStylable {
 
-  SVGAnimatedLength get height();
+  final SVGAnimatedLength height;
 
-  SVGAnimatedEnumeration get maskContentUnits();
+  final SVGAnimatedEnumeration maskContentUnits;
 
-  SVGAnimatedEnumeration get maskUnits();
+  final SVGAnimatedEnumeration maskUnits;
 
-  SVGAnimatedLength get width();
+  final SVGAnimatedLength width;
 
-  SVGAnimatedLength get x();
+  final SVGAnimatedLength x;
 
-  SVGAnimatedLength get y();
+  final SVGAnimatedLength y;
 }