Fix typo in `Map.values` getter.

sdk/lib/core/map.dart

 // Copyright (c) 2011, 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 dart.core;
 
 /**
  * An collection of key-value pairs, from which you retrieve a value
  * using its associated key.
  *
@@ skipping 226 matching lines @@
    *
    * The order of iteration is defined by the individual `Map` implementation,
    * but must be consistent between changes to the map.
    */
   Iterable<K> get keys;
 
   /**
    * The values of [this].
    *
    * The values are iterated in the order of their corresponding keys.
-   * This means that iterating [keys] and [values] in parrallel will
+   * This means that iterating [keys] and [values] in parallel will
    * provided matching pairs of keys and values.
    *
    * The returned iterable has an efficient `length` method based on the
    * [length] of the map. Its [Iterable.contains] method is based on
    * `==` comparison.
    */
   Iterable<V> get values;
 
   /**
    * The number of key-value pairs in the map.
    */
   int get length;
 
   /**
    * Returns true if there is no key-value pair in the map.
    */
   bool get isEmpty;
 
   /**
    * Returns true if there is at least one key-value pair in the map.
    */
   bool get isNotEmpty;
 }