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

pkg/serialization/lib/src/serialization_helpers.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.
 
 /**
  * This contains extra functions and classes useful for implementing
  * serialiation. Some or all of these will be removed once the functionality is
  * available in the core library.
  */
 library serialization_helpers;
 
 /**
  * A named function of one argument that just returns it. Useful for using
  * as a default value for a function parameter or other places where you want
  * to concisely provide a function that just returns its argument.
  */
 doNothing(x) => x;
 
 /** Concatenate two lists. Handle the case where one or both might be null. */
 // TODO(alanknight): Remove once issue 5342 is resolved.
 Iterable append(Iterable a, Iterable b) {
   if (a == null) {
-    return (b == null) ? [] : new List.from(b);
+    return (b == null) ? [] : new List.from(b, growable: true);
   }
-  if (b == null) return new List.from(a);
-  var result = new List.from(a);
+  if (b == null) return new List.from(a, growable: true);
+  var result = new List.from(a, growable: true);
   result.addAll(b);
   return result;
 }
 
 /**
  * Return a sorted version of [anIterable], using the default sort criterion.
  * Always returns a List, regardless of the type of [anIterable].
  */
 List sorted(anIterable) {
   var result = new List.from(anIterable);
@@ skipping 88 matching lines @@
  * for the moment.
  */
 values(x) {
   if (x is Iterable) return x;
   if (x is Map) return new ListLikeIterable(x);
   throw new ArgumentError("Invalid argument");
 }
 
 mapValues(x, f) {
   if (x is Set) return x.map(f).toSet();
-  if (x is Iterable) return x.map(f).toList();
+  if (x is Iterable) return x.map(f).toList(growable: true);
   if (x is Map) return new ListLikeIterable(x).map(f);
   throw new ArgumentError("Invalid argument");
 }
 
 /**
  * A class for iterating over things as if they were Lists, which primarily
  * means that forEach passes one argument, and map() returns a new Map
  * with the same keys as [collection] and values which haev been transformed
  * by the argument to map().
  */
@@ skipping 99 matching lines @@
   int get length => keys.length;
   void clear() {
     keys.clear();
     values.clear();
   }
   bool get isEmpty => keys.isEmpty;
 
   // Note that this is doing an equality comparison.
   bool containsValue(x) => values.contains(x);
 }