Add fromIterable(s) constructors in SplayTreeMap and LinkedHashMap.

sdk/lib/collection/linked_hash_map.dart

 // Copyright (c) 2013, 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.collection;
 
 /**
  * A hash-table based implementation of [Map].
  *
  * Keys insertion order is remembered, and keys are iterated in insertion order.
  * Values are iterated in their corresponding key's order.
  *
  * The keys of a `HashMap` must have consistent [Object.operator==]
  * and [Object.hashCode] implementations. This means that the `==` operator
  * must define a stable equivalence relation on the keys (reflexive,
  * anti-symmetric, transitive, and consistent over time), and that `hashCode`
  * must be the same for objects that are considered equal by `==`.
  *
  * The map allows `null` as a key.
  */
 class LinkedHashMap<K, V> implements Map<K, V> {
   external LinkedHashMap();
 
   factory LinkedHashMap.from(Map<K, V> other) {
     return new LinkedHashMap<K, V>()..addAll(other);
   }
 
+  factory LinkedHashMap.fromIterable(Iterable iterable,
+      {K key(element), V value(element)}) {
+    LinkedHashMap<K, V> map = new LinkedHashMap<K, V>();
+    Maps._fillMapWithMappedIterable(map, iterable, key: key, value: value);
+    return map;
+  }
+
+  factory LinkedHashMap.fromIterables(Iterable<K> keys, Iterable<V> values) {
+    LinkedHashMap<K, V> map = new LinkedHashMap<K, V>();
+    Maps._fillMapWithIterables(map, keys, values);
+    return map;
+  }
+
   external bool containsKey(Object key);
 
   external bool containsValue(Object value);
 
   external void addAll(Map<K, V> other);
 
   external V operator [](Object key);
 
   external void operator []=(K key, V value);
 
@@ skipping 11 matching lines @@
   external Iterable<V> get values;
 
   external int get length;
 
   external bool get isEmpty;
 
   external bool get isNotEmpty;
 
   String toString() => Maps.mapToString(this);
 }