Don't put private members in dart:html interfaces.

client/html/generated/html/frog/Node.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.
 
 class _NodeImpl extends _EventTargetImpl implements Node native "*Node" {
   _NodeListImpl get nodes() {
     final list = _childNodes;
     list._parent = this;
     return list;
   }
 
   void set nodes(Collection<Node> value) {
     // Copy list first since we don't want liveness during iteration.
     // TODO(jacobr): there is a better way to do this.
     List copy = new List.from(value);
     text = '';
     for (Node node in copy) {
       _appendChild(node);
     }
   }
 
   // TODO(jacobr): should we throw an exception if parent is already null?
   _NodeImpl remove() {
     if (this.parent != null) {
-      this.parent._removeChild(this);
+      final _NodeImpl parent = this.parent;
+      parent._removeChild(this);
     }
     return this;
   }
 
   _NodeImpl replaceWith(Node otherNode) {
     try {
-      this.parent._replaceChild(otherNode, this);
+      final _NodeImpl parent = this.parent;
+      parent._replaceChild(otherNode, this);
     } catch(var e) {
       
     };
     return this;
   }
 
 
   static final int ATTRIBUTE_NODE = 2;
 
   static final int CDATA_SECTION_NODE = 4;
@@ skipping 56 matching lines @@
 
   bool hasChildNodes() native;
 
   _NodeImpl insertBefore(_NodeImpl newChild, _NodeImpl refChild) native;
 
   _NodeImpl _removeChild(_NodeImpl oldChild) native "return this.removeChild(oldChild);";
 
   _NodeImpl _replaceChild(_NodeImpl newChild, _NodeImpl oldChild) native "return this.replaceChild(newChild, oldChild);";
 
 }