Fix incorrect type variable usage in copied code.

sdk/lib/internal/iterable.dart

 // Copyright (c) 2011, 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._internal;
 
 /**
  * Marker interface for [Iterable] subclasses that have an efficient
  * [length] implementation.
  */
@@ skipping 908 matching lines @@
       }
     }
     if (foundMatching) return result;
     throw IterableElementError.noElement();
   }
 
   static elementAt(Iterable iterable, int index) {
     if (index is! int) throw new ArgumentError.notNull("index");
     RangeError.checkNotNegative(index, "index");
     int elementIndex = 0;
-    for (E element in iterable) {
+    for (var element in iterable) {
       if (index == elementIndex) return element;
       elementIndex++;
     }
     throw new RangeError.index(index, iterable, "index", null, elementIndex);
   }
 
   static String join(Iterable iterable, [String separator]) {
     StringBuffer buffer = new StringBuffer();
     buffer.writeAll(iterable, separator);
     return buffer.toString();
@@ skipping 220 matching lines @@
  * Creates errors throw by [Iterable] when the element count is wrong.
  */
 abstract class IterableElementError {
   /** Error thrown thrown by, e.g., [Iterable.first] when there is no result. */
   static StateError noElement() => new StateError("No element");
   /** Error thrown by, e.g., [Iterable.single] if there are too many results. */
   static StateError tooMany() => new StateError("Too many elements");
   /** Error thrown by, e.g., [List.setRange] if there are too few elements. */
   static StateError tooFew() => new StateError("Too few elements");
 }