Updates to collection_patch.dart

tool/input_sdk/lib/collection/hash_set.dart

 // Copyright (c) 2013, 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.collection;
 
 /** Common parts of [HashSet] and [LinkedHashSet] implementations. */
 abstract class _HashSetBase<E> extends SetBase<E> {
 
   // The following two methods override the ones in SetBase.
@@ skipping 75 matching lines @@
    * The default equality and hashcode operations are assumed to work on all
    * objects.
    *
    * Likewise, if `equals` is [identical], `hashCode` is [identityHashCode]
    * and `isValidKey` is omitted, the resulting set is identity based,
    * and the `isValidKey` defaults to accepting all keys.
    * Such a map can be created directly using [HashSet.identity].
    */
   external factory HashSet({bool equals(E e1, E e2),
                             int hashCode(E e),
-                            bool isValidKey(potentialKey)});
+                            bool isValidKey(Object potentialKey)});
 
   /**
    * Creates an unordered identity-based set.
    *
    * Effectively a shorthand for:
    *
    *     new HashSet<E>(equals: identical,
    *                    hashCode: identityHashCode)
    */
   external factory HashSet.identity();
@@ skipping 22 matching lines @@
   }
 
   /**
    * Provides an iterator that iterates over the elements of this set.
    *
    * The order of iteration is unspecified,
    * but consistent between changes to the set.
    */
   Iterator<E> get iterator;
 }