Make DOMType the root of DOM implementation types.

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

Index: client/dom/generated/src/frog/MessagePort.dart
diff --git a/client/dom/generated/src/frog/MessagePort.dart b/client/dom/generated/src/frog/MessagePort.dart
index ce5f2f1269fe0b7ea1630d7a12b82ee95986e09d..e82ed0e1a4ff01427b9eaf3be40167c150be9c6f 100644
--- a/client/dom/generated/src/frog/MessagePort.dart
+++ b/client/dom/generated/src/frog/MessagePort.dart
@@ -1,11 +1,11 @@
 
-class MessagePortJS implements MessagePort native "*MessagePort" {
+class MessagePortJs extends DOMTypeJs implements MessagePort native "*MessagePort" {
 
   void addEventListener(String type, EventListener listener, [bool useCapture = null]) native;
 
   void close() native;
 
-  bool dispatchEvent(EventJS evt) native;
+  bool dispatchEvent(EventJs evt) native;
 
   void postMessage(String message, [List messagePorts = null]) native;
 
@@ -14,8 +14,4 @@ class MessagePortJS implements MessagePort native "*MessagePort" {
   void start() native;
 
   void webkitPostMessage(String message, [List transfer = null]) native;
-
-  var dartObjectLocalStorage;
-
-  String get typeName() native;
 }