Refactor the event-generation code to locate it in systemhtml.py.

client/html/generated/html/interface/DOMApplicationCache.dart

 // Copyright (c) 2012, 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.
 
 // WARNING: Do not edit - generated code.
 
 interface DOMApplicationCache extends EventTarget {
 
+  DOMApplicationCacheEvents get on();
+
   static final int CHECKING = 2;
 
   static final int DOWNLOADING = 3;
 
   static final int IDLE = 1;
 
   static final int OBSOLETE = 5;
 
   static final int UNCACHED = 0;
 
   static final int UPDATEREADY = 4;
 
   final int status;
 
-  DOMApplicationCacheEvents get on();
-
   void abort();
 
   void _addEventListener(String type, EventListener listener, [bool useCapture]);
 
   bool _dispatchEvent(Event evt);
 
   void _removeEventListener(String type, EventListener listener, [bool useCapture]);
 
   void swapCache();
 
@@ skipping 11 matching lines @@
   EventListenerList get error();
 
   EventListenerList get noUpdate();
 
   EventListenerList get obsolete();
 
   EventListenerList get progress();
 
   EventListenerList get updateReady();
 }