Fix some warnings.

lib/dom/templates/html/impl/impl_Node.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.
 
 /**
  * Lazy implementation of the child nodes of an element that does not request
  * the actual child nodes of an element until strictly necessary greatly
  * improving performance for the typical cases where it is not required.
  */
 class _ChildNodeListLazy implements NodeList {
@@ skipping 19 matching lines @@
   }
 
 
   void addAll(Collection<_NodeImpl> collection) {
     for (_NodeImpl node in collection) {
       _this.$dom_appendChild(node);
     }
   }
 
   _NodeImpl removeLast() {
-    final last = last();
-    if (last != null) {
-      _this.$dom_removeChild(last);
+    final result = last();
+    if (result != null) {
+      _this.$dom_removeChild(result);
     }
-    return last;
+    return result;
   }
 
   void clear() {
     _this.text = '';
   }
 
   void operator []=(int index, _NodeImpl value) {
     _this.$dom_replaceChild(value, this[index]);
   }
 
@@ skipping 21 matching lines @@
   void sort(int compare(Node a, Node b)) {
     throw new UnsupportedOperationException("Cannot sort immutable List.");
   }
 
   int indexOf(Node element, [int start = 0]) =>
       _Lists.indexOf(this, element, start, this.length);
 
   int lastIndexOf(Node element, [int start = 0]) =>
       _Lists.lastIndexOf(this, element, start);
 
-  // FIXME: implement thesee.
-  void setRange(int start, int length, List<Node> from, [int startFrom]) {
+  // FIXME: implement these.
+  void setRange(int start, int rangeLength, List<Node> from, [int startFrom]) {
     throw new UnsupportedOperationException(
         "Cannot setRange on immutable List.");
   }
-  void removeRange(int start, int length) {
+  void removeRange(int start, int rangeLength) {
     throw new UnsupportedOperationException(
         "Cannot removeRange on immutable List.");
   }
-  void insertRange(int start, int length, [Node initialValue]) {
+  void insertRange(int start, int rangeLength, [Node initialValue]) {
     throw new UnsupportedOperationException(
         "Cannot insertRange on immutable List.");
   }
-  NodeList getRange(int start, int length) =>
-    new _NodeListWrapper(_Lists.getRange(this, start, length, <Node>[]));
+  NodeList getRange(int start, int rangeLength) =>
+    new _NodeListWrapper(_Lists.getRange(this, start, rangeLength, <Node>[]));
 
   // -- end List<Node> mixins.
 
   // TODO(jacobr): benchmark whether this is more efficient or whether caching
   // a local copy of $dom_childNodes is more efficient.
   int get length() => _this.$dom_childNodes.length;
 
   _NodeImpl operator[](int index) => _this.$dom_childNodes[index];
 }
 
@@ skipping 26 matching lines @@
       final _NodeImpl parent = this.parent;
       parent.$dom_replaceChild(otherNode, this);
     } catch(var e) {
       
     };
     return this;
   }
 
 $!MEMBERS
 }