Adding @domName annotations to impl files what were missing them.

sdk/lib/html/templates/html/impl/impl_EventTarget.darttemplate

 // 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.
 
 part of html;
 
 class Events {
   /* Raw event target. */
   final EventTarget _ptr;
 
@@ skipping 31 matching lines @@
 
   void _add(EventListener listener, bool useCapture) {
     _ptr.$dom_addEventListener(_type, listener, useCapture);
   }
 
   void _remove(EventListener listener, bool useCapture) {
     _ptr.$dom_removeEventListener(_type, listener, useCapture);
   }
 }
 
-
+/// @domName $DOMNAME
 class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 
   /** @domName EventTarget.addEventListener, EventTarget.removeEventListener, EventTarget.dispatchEvent */
   Events get on => new Events(this);
 $!MEMBERS
 }