Move frog dart:dom from fields to getters/setters.

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

 
 class HTMLFontElement extends HTMLElement native "*HTMLFontElement" {
 
-  String color;
+  String get color() native "return this.color;";
 
-  String face;
+  void set color(String value) native "this.color = value;";
 
-  String size;
+  String get face() native "return this.face;";
+
+  void set face(String value) native "this.face = value;";
+
+  String get size() native "return this.size;";
+
+  void set size(String value) native "this.size = value;";
 }