Add "contains" method to Collection.

runtime/lib/growable_array.dart

Index: runtime/lib/growable_array.dart
diff --git a/runtime/lib/growable_array.dart b/runtime/lib/growable_array.dart
index 58ec00cb106452ad3f0b3dab97503f9d8170925f..e93a9fe4e5afb5d78ce7c263defe3cdf7ffe26f7 100644
--- a/runtime/lib/growable_array.dart
+++ b/runtime/lib/growable_array.dart
@@ -166,9 +166,9 @@ class _GrowableObjectArray<T> implements List<T> {
     _setData(new_data);
   }
 
-  /**
-   * Collection interface.
-   */
+  // Collection interface.
+
+  bool contains(T element) => Collections.contains(this, element);
 
   void forEach(f(T element)) {
     // TODO(srdjan): Use Collections.forEach(this, f);
@@ -216,28 +216,6 @@ class _GrowableObjectArray<T> implements List<T> {
   }
 
   Iterator<T> iterator() {
-    return new VariableSizeArrayIterator<T>(this);
-  }
-}
-
-
-// Iterator for arrays with variable size.
-class VariableSizeArrayIterator<T> implements Iterator<T> {
-  VariableSizeArrayIterator(_GrowableObjectArray<T> array)
-      : _array = array,  _pos = 0 {
+    return new SequenceIterator<T>(this);
   }
-
-  bool hasNext() {
-    return _array.length > _pos;
-  }
-
-  T next() {
-    if (!hasNext()) {
-      throw const NoMoreElementsException();
-    }
-    return _array[_pos++];
-  }
-
-  final _GrowableObjectArray<T> _array;
-  int _pos;
 }