Use fields in hidden native DOM classes instead of getters/setters.

client/dom/generated/src/frog/HTMLSelectElement.dart

Index: client/dom/generated/src/frog/HTMLSelectElement.dart
diff --git a/client/dom/generated/src/frog/HTMLSelectElement.dart b/client/dom/generated/src/frog/HTMLSelectElement.dart
index 0d212c2d00fafa1da9c30a9d772faadec16b5ec3..2e0a88abd5211b7e8e2c8169fd835fce52521d21 100644
--- a/client/dom/generated/src/frog/HTMLSelectElement.dart
+++ b/client/dom/generated/src/frog/HTMLSelectElement.dart
@@ -1,55 +1,37 @@
 
 class _HTMLSelectElementJs extends _HTMLElementJs implements HTMLSelectElement native "*HTMLSelectElement" {
 
-  bool get autofocus() native "return this.autofocus;";
+  bool autofocus;
 
-  void set autofocus(bool value) native "this.autofocus = value;";
+  bool disabled;
 
-  bool get disabled() native "return this.disabled;";
+  final _HTMLFormElementJs form;
 
-  void set disabled(bool value) native "this.disabled = value;";
+  final _NodeListJs labels;
 
-  _HTMLFormElementJs get form() native "return this.form;";
+  int length;
 
-  _NodeListJs get labels() native "return this.labels;";
+  bool multiple;
 
-  int get length() native "return this.length;";
+  String name;
 
-  void set length(int value) native "this.length = value;";
+  final _HTMLOptionsCollectionJs options;
 
-  bool get multiple() native "return this.multiple;";
+  bool required;
 
-  void set multiple(bool value) native "this.multiple = value;";
+  int selectedIndex;
 
-  String get name() native "return this.name;";
+  int size;
 
-  void set name(String value) native "this.name = value;";
+  final String type;
 
-  _HTMLOptionsCollectionJs get options() native "return this.options;";
+  final String validationMessage;
 
-  bool get required() native "return this.required;";
+  final _ValidityStateJs validity;
 
-  void set required(bool value) native "this.required = value;";
+  String value;
 
-  int get selectedIndex() native "return this.selectedIndex;";
-
-  void set selectedIndex(int value) native "this.selectedIndex = value;";
-
-  int get size() native "return this.size;";
-
-  void set size(int value) native "this.size = value;";
-
-  String get type() native "return this.type;";
-
-  String get validationMessage() native "return this.validationMessage;";
-
-  _ValidityStateJs get validity() native "return this.validity;";
-
-  String get value() native "return this.value;";
-
-  void set value(String value) native "this.value = value;";
-
-  bool get willValidate() native "return this.willValidate;";
+  final bool willValidate;
 
   void add(_HTMLElementJs element, _HTMLElementJs before) native;