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

tests/json/json_test.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.
 
 library json_tests;
 import 'dart:json' as json;
 import 'dart:html';
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_config.dart';
 
@@ skipping 72 matching lines @@
     expect(json.stringify(null), equals('null'));
     expect(json.stringify(' hi there" bob '), equals('" hi there\\" bob "'));
     expect(json.stringify('hi\\there'), equals('"hi\\\\there"'));
     // TODO(devoncarew): these tests break the dartium build
     //expect(json.stringify('hi\nthere'), equals('"hi\\nthere"'));
     //expect(json.stringify('hi\r\nthere'), equals('"hi\\r\\nthere"'));
     expect(json.stringify(''), equals('""'));
 
     // Lists.
     expect(json.stringify([]), equals('[]'));
-    expect(json.stringify(new List.fixedLength(0)), equals('[]'));
-    expect(json.stringify(new List.fixedLength(3)), equals('[null,null,null]'));
+    expect(json.stringify(new List(0)), equals('[]'));
+    expect(json.stringify(new List(3)), equals('[null,null,null]'));
     validateRoundTrip([3, -4.5, null, true, 'hi', false]);
     expect(json.stringify([[3], [], [null], ['hi', true]]),
       equals('[[3],[],[null],["hi",true]]'));
 
     // Maps.
     expect(json.stringify({}), equals('{}'));
     expect(json.stringify(new Map()), equals('{}'));
     expect(json.stringify({'x':{}}), equals('{"x":{}}'));
     expect(json.stringify({'x':{'a':3}}), equals('{"x":{"a":3}}'));
 
@@ skipping 47 matching lines @@
 
 /**
  * Checks that the argument can be converted to a JSON string and
  * back, and produce something equivalent to the argument.
  */
 validateRoundTrip(expected) {
   expect(json.parse(json.stringify(expected)), equals(expected));
 }