Change new List(n) to return fixed length list.

pkg/serialization/lib/src/basic_rule.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 serialization;
 
 // TODO(alanknight): Figure out how to reasonably separate out the things
 // that require reflection without making the API more awkward. Or if that is
 // in fact necessary. Maybe the tree-shaking will just remove it if unused.
 
@@ skipping 112 matching lines @@
   /**
    * Configure this instance to use lists accessing fields by index as its
    * output. Instances can either produce maps or lists. The list representation
    * is much more compact and used by default. The map representation is
    * much easier to debug. The default is to use lists.
    */
   configureForLists() {
     useMaps = false;
   }
 
-  /** Create either a list or a map to hold the object's state, depending
+  /**
+   * Create either a list or a map to hold the object's state, depending
    * on the [useMaps] variable. If using a Map, we wrap it in order to keep
    * the protocol compatible. See [configureForLists]/[configureForMaps].
+   *
+   * If a list is returned, it is growable.
    */
-   createStateHolder() =>
-     useMaps ? new _MapWrapper(fields.contents) : new List(fields.length);
+   createStateHolder() {
+     if (useMaps) return new _MapWrapper(fields.contents);
+     List list = [];
+     list.length = fields.length;
+     return list;
+   }
 
   /**
    * Wrap the state if it's passed in as a map, and if the keys are references,
    * resolve them to the strings we expect. We leave the previous keys in there
    * as well, as they shouldn't be harmful, and it costs more to remove them.
    */
    makeIndexableByNumber(state) {
      if (!(state is Map)) return state;
      // TODO(alanknight): This is quite inefficient, and we do it twice per
      // instance. If the keys are references, we need to turn them into strings
@@ skipping 474 matching lines @@
   _MapWrapper(this.fieldList) : _map = new Map();
   _MapWrapper.fromMap(this._map, this.fieldList);
 
   operator [](key) => _map[fieldList[key].name];
 
   operator []=(key, value) { _map[fieldList[key].name] = value; }
   get length => _map.length;
 
   asMap() => _map;
 }