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

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

 
 class _WorkerContextJs extends _DOMTypeJs implements WorkerContext native "*WorkerContext" {
 
   static final int PERSISTENT = 1;
 
   static final int TEMPORARY = 0;
 
-  _WorkerLocationJs get location() native "return this.location;";
+  _WorkerLocationJs location;
 
-  void set location(_WorkerLocationJs value) native "this.location = value;";
+  _WorkerNavigatorJs navigator;
 
-  _WorkerNavigatorJs get navigator() native "return this.navigator;";
+  EventListener onerror;
 
-  void set navigator(_WorkerNavigatorJs value) native "this.navigator = value;";
+  _WorkerContextJs self;
 
-  EventListener get onerror() native "return this.onerror;";
+  final _IDBFactoryJs webkitIndexedDB;
 
-  void set onerror(EventListener value) native "this.onerror = value;";
+  final _NotificationCenterJs webkitNotifications;
 
-  _WorkerContextJs get self() native "return this.self;";
-
-  void set self(_WorkerContextJs value) native "this.self = value;";
-
-  _IDBFactoryJs get webkitIndexedDB() native "return this.webkitIndexedDB;";
-
-  _NotificationCenterJs get webkitNotifications() native "return this.webkitNotifications;";
-
-  _DOMURLJs get webkitURL() native "return this.webkitURL;";
+  final _DOMURLJs webkitURL;
 
   void addEventListener(String type, EventListener listener, [bool useCapture = null]) native;
 
   void clearInterval(int handle) native;
 
   void clearTimeout(int handle) native;
 
   void close() native;
 
   bool dispatchEvent(_EventJs evt) native;
@@ skipping 11 matching lines @@
   int setTimeout(TimeoutHandler handler, int timeout) native;
 
   void webkitRequestFileSystem(int type, int size, [FileSystemCallback successCallback = null, ErrorCallback errorCallback = null]) native;
 
   _DOMFileSystemSyncJs webkitRequestFileSystemSync(int type, int size) native;
 
   _EntrySyncJs webkitResolveLocalFileSystemSyncURL(String url) native;
 
   void webkitResolveLocalFileSystemURL(String url, [EntryCallback successCallback = null, ErrorCallback errorCallback = null]) native;
 }