Moving ListBase, FixedLengthListMixin and UmodifiableListMixin to collection.

sdk/lib/collection/collections.dart

 // 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 dart.collection;
 
 /**
  * This class provides default implementations for Iterables (including Lists).
  *
  * Once Dart receives Mixins it will be replaced with mixin classes.
  */
+@deprecated
 class IterableMixinWorkaround {
   static bool contains(Iterable iterable, var element) {
     for (final e in iterable) {
       if (element == e) return true;
     }
     return false;
   }
 
   static void forEach(Iterable iterable, void f(o)) {
     for (final e in iterable) {
@@ skipping 406 matching lines @@
  * The source of the elements may be a [List] or any [Iterable] with
  * efficient [Iterable.length] and [Iterable.elementAt].
  */
 class UnmodifiableListView<E> extends UnmodifiableListBase<E> {
   Iterable<E> _source;
   /** Create an unmodifiable list backed by [source]. */
   UnmodifiableListView(Iterable<E> source) : _source = source;
   int get length => _source.length;
   E operator[](int index) => _source.elementAt(index);
 }