Make html lists print a nice toString method.

tools/dom/templates/html/impl/impl_Element.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 $LIBRARYNAME;
 
 // TODO(jacobr): use _Lists.dart to remove some of the duplicated
 // functionality.
 class _ChildrenElementList implements List {
   // Raw Element.
@@ skipping 264 matching lines @@
     return IterableMixinWorkaround.min(this, compare);
   }
 
   Element max([int compare(Element a, Element b)]) {
     return IterableMixinWorkaround.max(this, compare);
   }
 
   Map<int, Element> asMap() {
     return IterableMixinWorkaround.asMapList(this);
   }
+
+  String toString() {
+    StringBuffer buffer = new StringBuffer('[');
+    buffer.writeAll(this, ', ');
+    buffer.write(']');
+    return buffer.toString();
+  }
 }
 
 // TODO(jacobr): this is an inefficient implementation but it is hard to see
 // a better option given that we cannot quite force NodeList to be an
 // ElementList as there are valid cases where a NodeList JavaScript object
 // contains Node objects that are not Elements.
 class _FrozenElementList implements List {
   final List<Node> _nodeList;
 
   _FrozenElementList._wrap(this._nodeList);
@@ skipping 190 matching lines @@
     return IterableMixinWorkaround.min(this, compare);
   }
 
   Element max([int compare(Element a, Element b)]) {
     return IterableMixinWorkaround.max(this, compare);
   }
 
   Map<int, Element> asMap() {
     return IterableMixinWorkaround.asMapList(this);
   }
+
+  String toString() {
+    StringBuffer buffer = new StringBuffer('[');
+    buffer.writeAll(this, ', ');
+    buffer.write(']');
+    return buffer.toString();
+  }
 }
 
 class _FrozenElementListIterator implements Iterator<Element> {
   final _FrozenElementList _list;
   int _index = -1;
   Element _current;
 
   _FrozenElementListIterator(this._list);
 
   /**
@@ skipping 467 matching lines @@
     } else if (JS('bool', '!!#.mozMatchesSelector', this)) {
       return JS('bool', '#.mozMatchesSelector(#)', this, selectors);
     } else if (JS('bool', '!!#.msMatchesSelector', this)) {
       return JS('bool', '#.msMatchesSelector(#)', this, selectors);
     }
     throw new UnsupportedError("Not supported on this platform");
   }
 $else
 $endif
 
+  /** 
+   * Print out a String representation of this Element. By default, this is
+   * this Element's tagName.
+   */
+  String toString() => this.tagName;
+
 $!MEMBERS
 }
 
 final _START_TAG_REGEXP = new RegExp('<(\\w+)');
 class _ElementFactoryProvider {
   static const _CUSTOM_PARENT_TAG_MAP = const {
     'body' : 'html',
     'head' : 'html',
     'caption' : 'table',
     'td': 'tr',
@@ skipping 139 matching lines @@
   const ScrollAlignment._internal(this._value);
   toString() => 'ScrollAlignment.$_value';
 
   /// Attempt to align the element to the top of the scrollable area.
   static const TOP = const ScrollAlignment._internal('TOP');
   /// Attempt to center the element in the scrollable area.
   static const CENTER = const ScrollAlignment._internal('CENTER');
   /// Attempt to align the element to the bottom of the scrollable area.
   static const BOTTOM = const ScrollAlignment._internal('BOTTOM');
 }