Fix some warnings.

lib/dom/templates/immutable_list_mixin.darttemplate

   // -- start List<$E> mixins.
   // $E is the element type.
 
   // From Iterable<$E>:
 
   Iterator<$E> iterator() {
     // Note: NodeLists are not fixed size. And most probably length shouldn't
     // be cached in both iterator _and_ forEach method. For now caching it
     // for consistency.
     return new _FixedSizeListIterator<$E>(this);
@@ skipping 33 matching lines @@
   }
 
   int indexOf($E element, [int start = 0]) =>
       _Lists.indexOf(this, element, start, this.length);
 
   int lastIndexOf($E element, [int start = 0]) =>
       _Lists.lastIndexOf(this, element, start);
 
   $E last() => this[length - 1];
 
-  // FIXME: implement thesee.
-  void setRange(int start, int length, List<$E> from, [int startFrom]) {
+  // FIXME: implement these.
+  void setRange(int start, int rangeLength, List<$E> 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, [$E initialValue]) {
+  void insertRange(int start, int rangeLength, [$E initialValue]) {
     throw new UnsupportedOperationException("Cannot insertRange on immutable List.");
   }
-  List<$E> getRange(int start, int length) =>
-      _Lists.getRange(this, start, length, <$E>[]);
+  List<$E> getRange(int start, int rangeLength) =>
+      _Lists.getRange(this, start, rangeLength, <$E>[]);
 
   // -- end List<$E> mixins.