Use iterator, moveNext(), current.

sdk/lib/core/iterable.dart

Index: sdk/lib/core/iterable.dart
diff --git a/sdk/lib/core/iterable.dart b/sdk/lib/core/iterable.dart
index f3cfa9354aa126d6d0df399dae4b52ca623f6c24..92c9330f0d7246887c10dbff77a28256cf50f8fd 100644
--- a/sdk/lib/core/iterable.dart
+++ b/sdk/lib/core/iterable.dart
@@ -20,7 +20,7 @@ abstract class Iterable<E> {
   /**
    * Returns an [Iterator] that iterates over this [Iterable] object.
    */
-  Iterator<E> iterator();
+  Iterator<E> get iterator;
 
   /**
    * Returns a new collection with the elements [: f(e) :]
@@ -115,5 +115,5 @@ abstract class Iterable<E> {
   /**
    * Returns true if there is no element in this collection.
    */
-  bool get isEmpty => !iterator().hasNext;
+  bool get isEmpty => !iterator.moveNext();
 }