Fixing File API test.

tools/dom/templates/html/dart2js/html_dart2js.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.
 
 // DO NOT EDIT - unless you are editing documentation as per:
 // https://code.google.com/p/dart/wiki/ContributingHTMLDocumentation
 // Auto-generated dart:html library.
 
 /**
  * HTML elements and other resources for web-based applications that need to
@@ skipping 103 matching lines @@
 
 Element query(String selector) => document.query(selector);
 ElementList queryAll(String selector) => document.queryAll(selector);
 
 // Workaround for tags like <cite> that lack their own Element subclass --
 // Dart issue 1990.
 class HtmlElement extends Element native "HTMLElement" {
   factory HtmlElement() { throw new UnsupportedError("Not supported"); }
 }
 
+// EntryArray type was removed, so explicitly adding it to allow support for
+// older Chrome versions.
+// Issue #12573.
+abstract class _EntryArray implements List<Entry> native "EntryArray" {}
+
 // Support for Send/ReceivePortSync.
 int _getNewIsolateId() {
   if (JS('bool', r'!window.$dart$isolate$counter')) {
     JS('void', r'window.$dart$isolate$counter = 1');
   }
   return JS('int', r'window.$dart$isolate$counter++');
 }
 
 // Fast path to invoke JS send port.
 _callPortSync(int id, message) {
   return JS('var', r'ReceivePortSync.dispatchCall(#, #)', id, message);
 }