Add Iterable.fold (and Stream.fold) which replace `reduce`.

tools/dom/templates/html/impl/impl_Node.darttemplate

Index: tools/dom/templates/html/impl/impl_Node.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_Node.darttemplate b/tools/dom/templates/html/impl/impl_Node.darttemplate
index 8aa2428487258054f108cd3e89f0a5b860b44667..bd9eeb20ddd1916c182ae648be32fdc4105c12d6 100644
--- a/tools/dom/templates/html/impl/impl_Node.darttemplate
+++ b/tools/dom/templates/html/impl/impl_Node.darttemplate
@@ -150,6 +150,11 @@ $endif
     return IterableMixinWorkaround.reduce(this, initialValue, combine);

[Lasse Reichstein Nielsen, 2013/04/04 08:35:18]

and here.

[floitsch, 2013/04/05 16:10:03]

ditto.

   }
 
+  dynamic fold(dynamic initialValue,
+      dynamic combine(dynamic previousValue, Node element)) {
+    return IterableMixinWorkaround.fold(this, initialValue, combine);
+  }
+
   String join([String separator]) {
     return IterableMixinWorkaround.joinList(this, separator);
   }