Reapply "Make Map constructors return LinkedHashMap."

sdk/lib/core/map.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.
 
 part of dart.core;
 
 /**
  * An unordered collection of key-value pairs,
  * from which you retrieve a value by using its associated key.
  *
  * Each key must be unique.
  * Null values are supported, but null keys are not.
  */
 abstract class Map<K, V> {
   /**
    * Creates a Map instance with the default implementation.
    */
-  factory Map() => new HashMap<K, V>();
+  factory Map() = LinkedHashMap<K, V>;
 
   /**
    * Creates a Map instance that contains all key-value pairs of [other].
    */
-  factory Map.from(Map<K, V> other) => new HashMap<K, V>.from(other);
+  factory Map.from(Map<K, V> other) = LinkedHashMap<K, V>.from;
 
   /**
    * Creates a Map instance
    * where the keys and values are computed from the [iterable].
    *
    * For each element of the [iterable] this constructor computes a key-value
    * pair, by applying [key] and [value] respectively.
    *
-   * The keys computed by the source [iterable] 
+   * The keys computed by the source [iterable]
    * do not need to be unique. The last
    * occurrence of a key will simply overwrite any previous value.
    *
    * If no values are specified for [key] and [value] the default is the
    * identity function.
    */
   factory Map.fromIterable(Iterable<K> iterable,
-      {K key(element), V value(element)}) = HashMap<K, V>.fromIterable;
+      {K key(element), V value(element)}) = LinkedHashMap<K, V>.fromIterable;
 
   /**
    * Creates a Map instance associating the given [keys] to [values].
    *
    * This constructor iterates over [keys] and [values] and maps each element of
    * [keys] to the corresponding element of [values].
    *
    * If [keys] contains the same object multiple times, the last occurrence
    * overwrites the previous value.
    *
    * It is an error if the two [Iterable]s don't have the same length.
    */
   factory Map.fromIterables(Iterable<K> keys, Iterable<V> values)
-      = HashMap<K, V>.fromIterables;
+      = LinkedHashMap<K, V>.fromIterables;
 
   /**
    * Returns true if this map contains the given value.
    */
   bool containsValue(Object value);
 
   /**
    * Returns true if this map contains the given key.
    */
   bool containsKey(Object key);
@@ skipping 70 matching lines @@
   /**
    * Returns true if there is no {key, value} pair in the map.
    */
   bool get isEmpty;
 
   /**
    * Returns true if there is at least one {key, value} pair in the map.
    */
   bool get isNotEmpty;
 }