Revert "Remove deprecated mappedBy."

utils/template/utils.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.
 
 // Collection<T> supports most of the ES 5 Array methods, but it's missing
 // map and reduce.
 
 // TODO(jmesserly): we might want a version of this that return an iterable,
 // however JS, Python and Ruby versions are all eager.
-List map(Iterable source, mapper(source)) {
+List mappedBy(Iterable source, mapper(source)) {
   List result = new List();
   if (source is List) {
     List list = source; // TODO: shouldn't need this
     result.length = list.length;
     for (int i = 0; i < list.length; i++) {
       result[i] = mapper(list[i]);
     }
   } else {
     for (final item in source) {
       result.add(mapper(item));
@@ skipping 25 matching lines @@
     }
     result.add(mapper(x.current, y.current));
   }
   if (y.moveNext()) {
     throw new ArgumentError();
   }
   return result;
 }