Get rid of a lot of () for getters.

lib/html/src/OverflowEvent.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.
 
 interface OverflowEvent extends Event default OverflowEventWrappingImplementation {
 
   OverflowEvent(int orient, bool horizontalOverflow, bool verticalOverflow);
 
   static const int BOTH = 2;
 
   static const int HORIZONTAL = 0;
 
   static const int VERTICAL = 1;
 
-  bool get horizontalOverflow();
+  bool get horizontalOverflow;
 
-  int get orient();
+  int get orient;
 
-  bool get verticalOverflow();
+  bool get verticalOverflow;
 }