Type check fixes for Dartium tests.

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

 // 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.
 
 part of html;
 
 // TODO(jacobr): use _Lists.dart to remove some of the duplicated
 // functionality.
 class _ChildrenElementList implements List {
   // Raw Element.
@@ skipping 48 matching lines @@
 
   String join([String separator]) {
     return Collections.joinList(this, separator);
   }
 
   List mappedBy(f(Element element)) {
     return new MappedList<Element, dynamic>(this, f);
   }
 
   Iterable<Element> where(bool f(Element element))
-      => new WhereIterable<Element>(this, f);
+      => new WhereIterable(this, f);
 
   bool get isEmpty {
     return _element.$dom_firstElementChild == null;
   }
 
   List<Element> take(int n) {
     return new ListView<Element>(this, 0, n);
   }
 
   Iterable<Element> takeWhile(bool test(Element value)) {
@@ skipping 162 matching lines @@
 
   String join([String separator]) {
     return Collections.joinList(this, separator);
   }
 
   List mappedBy(f(Element element)) {
     return new MappedList<Element, dynamic>(this, f);
   }
 
   Iterable<Element> where(bool f(Element element))
-      => new WhereIterable<Element>(this, f);
+      => new WhereIterable(this, f);
 
   bool every(bool f(Element element)) {
     for(Element element in this) {
       if (!f(element)) {
         return false;
       }
     };
     return true;
   }
 
@@ skipping 618 matching lines @@
 $if DART2JS
   // Optimization to improve performance until the dart2js compiler inlines this
   // method.
   static dynamic createElement_tag(String tag) =>
       JS('Element', 'document.createElement(#)', tag);
 $else
   static Element createElement_tag(String tag) =>
       document.$dom_createElement(tag);
 $endif
 }