Use 'field' syntax in dart:dom interfaces.

client/dom/generated/src/interface/SVGPathSegCurvetoCubicSmoothRel.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 SVGPathSegCurvetoCubicSmoothRel extends SVGPathSeg {
 
-  num get x();
+  num x;
 
-  void set x(num value);
+  num x2;
 
-  num get x2();
+  num y;
 
-  void set x2(num value);
-
-  num get y();
-
-  void set y(num value);
-
-  num get y2();
-
-  void set y2(num value);
+  num y2;
 }