Reapply "Make Map constructors return LinkedHashMap."

tests/corelib/linked_hash_map_from_iterable_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.
 
 import "package:expect/expect.dart";
 import 'dart:collection';
 
 main() {
   defaultFunctionValuesTest();
   defaultKeyFunctionTest();
   defaultValueFunctionTest();
   noDefaultValuesTest();
   emptyIterableTest();
   equalElementsTest();
   genericTypeTest();
 }
 
 void defaultFunctionValuesTest() {
   var map = new LinkedHashMap.fromIterable([1, 2, 3]);
 
   Expect.isTrue(map is Map);
   Expect.isTrue(map is LinkedHashMap);
-  Expect.isFalse(map is HashMap);
 
   Expect.equals(3, map.length);
   Expect.equals(3, map.keys.length);
   Expect.equals(3, map.values.length);
 
   Expect.equals(1, map[1]);
   Expect.equals(2, map[2]);
   Expect.equals(3, map[3]);
 }
 
 void defaultKeyFunctionTest() {
   var map = new LinkedHashMap.fromIterable([1, 2, 3], value: (x) => x + 1);
 
   Expect.isTrue(map is Map);
   Expect.isTrue(map is LinkedHashMap);
-  Expect.isFalse(map is HashMap);
 
   Expect.equals(3, map.length);
   Expect.equals(3, map.keys.length);
   Expect.equals(3, map.values.length);
 
   Expect.equals(2, map[1]);
   Expect.equals(3, map[2]);
   Expect.equals(4, map[3]);
 }
 
 void defaultValueFunctionTest() {
   var map = new LinkedHashMap.fromIterable([1, 2, 3], key: (x) => x + 1);
 
   Expect.isTrue(map is Map);
   Expect.isTrue(map is LinkedHashMap);
-  Expect.isFalse(map is HashMap);
 
   Expect.equals(3, map.length);
   Expect.equals(3, map.keys.length);
   Expect.equals(3, map.values.length);
 
   Expect.equals(1, map[2]);
   Expect.equals(2, map[3]);
   Expect.equals(3, map[4]);
 }
 
 void noDefaultValuesTest() {
   var map = new LinkedHashMap.fromIterable([1, 2, 3],
       key: (x) => x + 1, value: (x) => x - 1);
 
   Expect.isTrue(map is Map);
   Expect.isTrue(map is LinkedHashMap);
-  Expect.isFalse(map is HashMap);
 
   Expect.equals(3, map.length);
   Expect.equals(3, map.keys.length);
   Expect.equals(3, map.values.length);
 
   Expect.equals(0, map[2]);
   Expect.equals(1, map[3]);
   Expect.equals(2, map[4]);
 }
 
 void emptyIterableTest() {
   var map = new LinkedHashMap.fromIterable([]);
   Expect.isTrue(map is Map);
   Expect.isTrue(map is LinkedHashMap);
-  Expect.isFalse(map is HashMap);
 
   Expect.equals(0, map.length);
   Expect.equals(0, map.keys.length);
   Expect.equals(0, map.values.length);
 }
 
 void equalElementsTest() {
   var map = new LinkedHashMap.fromIterable([1, 2, 2], key: (x) => x + 1);
 
   Expect.isTrue(map is Map);
   Expect.isTrue(map is LinkedHashMap);
-  Expect.isFalse(map is HashMap);
 
   Expect.equals(2, map.length);
   Expect.equals(2, map.keys.length);
   Expect.equals(2, map.values.length);
 
   Expect.equals(1, map[2]);
   Expect.equals(2, map[3]);
 }
 
 void genericTypeTest() {
   var map = new LinkedHashMap<int, String>.fromIterable([1, 2, 3], value: (x) => '$x');
   Expect.isTrue(map is Map<int, String>);
   Expect.isTrue(map is LinkedHashMap<int, String>);
 
   // Make sure it is not just LinkedHashMap<dynamic, dynamic>.
   Expect.isFalse(map is LinkedHashMap<String, dynamic>);
   Expect.isFalse(map is LinkedHashMap<dynamic, int>);
 }