Add reduce to Collection.

runtime/lib/growable_array.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.
 
 class GrowableObjectArray<T> implements List<T> {
   factory GrowableObjectArray._uninstantiable() {
     throw const UnsupportedOperationException(
         "GrowableObjectArray can only be allocated by the VM");
   }
 
@@ skipping 162 matching lines @@
     for (int i = 0; i < length; i++) {
       f(this[i]);
     }
   }
 
   Collection map(f(T element)) {
     return Collections.map(this,
                            new GrowableObjectArray.withCapacity(length), f);
   }
 
+  Dynamic reduce(Dynamic initialValue,
+                 Dynamic combine(Dynamic previousValue, E element)) {
+    return Collections.reduce(this, initialValue, combine);
+  }
+
   Collection<T> filter(bool f(T element)) {
     return Collections.filter(this, new GrowableObjectArray<T>(), f);
   }
 
   bool every(bool f(T element)) {
     return Collections.every(this, f);
   }
 
   bool some(bool f(T element)) {
     return Collections.some(this, f);
@@ skipping 34 matching lines @@
   T next() {
     if (!hasNext()) {
       throw const NoMoreElementsException();
     }
     return _array[_pos++];
   }
 
   final GrowableObjectArray<T> _array;
   int _pos;
 }