Revert "Remove deprecated mappedBy."

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.
@@ skipping 303 matching lines @@
   }
 
   static Iterable map(Iterable iterable, f(var element)) {
     return new MappedIterable(iterable, f);
   }
 
   static Iterable mapList(List list, f(var element)) {
     return new MappedListIterable(list, f);
   }
 
+  static List mappedByList(List list, f(var element)) {
+    // This is currently a List as well as an Iterable.
+    return new MappedList(list, f);
+  }
+
   static Iterable expand(Iterable iterable, Iterable f(var element)) {
     return new ExpandIterable(iterable, f);
   }
 
   static Iterable takeList(List list, int n) {
     // The generic type is currently lost. It will be fixed with mixins.
     // This is currently a List as well as an Iterable.
     return new SubListIterable(list, 0, n);
   }
 
@@ skipping 128 matching lines @@
   static String joinList(List list, [String separator])
       => IterableMixinWorkaround.joinList(list, separator);
 
   /** Deprecated. Use the same method in [IterableMixinWorkaround] instead.*/
   @deprecated
   static Iterable where(Iterable iterable, bool f(var element))
       => IterableMixinWorkaround.where(iterable, f);
 
   /** Deprecated. Use the same method in [IterableMixinWorkaround] instead.*/
   @deprecated
+  static List mappedByList(List list, f(var element))
+      => IterableMixinWorkaround.mappedByList(list, f);
+
+  /** Deprecated. Use the same method in [IterableMixinWorkaround] instead.*/
+  @deprecated
   static Iterable takeList(List list, int n)
       => IterableMixinWorkaround.takeList(list, n);
 
   /** Deprecated. Use the same method in [IterableMixinWorkaround] instead.*/
   @deprecated
   static Iterable takeWhile(Iterable iterable, bool test(var value))
       => IterableMixinWorkaround.takeWhile(iterable, test);
 
   /** Deprecated. Use the same method in [IterableMixinWorkaround] instead.*/
   @deprecated
@@ skipping 15 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);
 }