Use language or userlanguage (IE) depending on what's defined in the browser.

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index 0e82128678b47b0b0d82e8f243460fe717558d18..95d13d67bec1432d4909d387f9552948ffed1e48 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -6017,27 +6017,6 @@ class DirectoryReaderSync native "*DirectoryReaderSync" {
 // BSD-style license that can be found in the LICENSE file.
 
 
-/**
- * Represents an HTML <div> element.
- *
- * The [DivElement] is a generic container for content and does not have any
- * special significance. It is functionally similar to [SpanElement].
- *
- * The [DivElement] is a block-level element, as opposed to [SpanElement],
- * which is an inline-level element.
- *
- * Example usage:
- *
- *     DivElement div = new DivElement();
- *     div.text = 'Here's my new DivElem
- *     document.body.elements.add(elem);
- *
- * See also:
- *
- * * [HTML <div> element](http://www.w3.org/TR/html-markup/div.html) from W3C.
- * * [Block-level element](http://www.w3.org/TR/CSS2/visuren.html#block-boxes) from W3C.
- * * [Inline-level element](http://www.w3.org/TR/CSS2/visuren.html#inline-boxes) from W3C.
- */
 /// @domName HTMLDivElement; @docsEditable true
 class DivElement extends Element implements Element native "*HTMLDivElement" {
 
@@ -6076,7 +6055,6 @@ class Document extends Node  native "*Document"
   /// @domName Document.cookie; @docsEditable true
   String cookie;
 
-  /// Returns the [Window] associated with the document.
   /// @domName Document.defaultView; @docsEditable true
   Window get window => _convertNativeToDart_Window(this._window);
   @JSName('defaultView')
@@ -12796,16 +12774,6 @@ class MemoryInfo native "*MemoryInfo" {
 // BSD-style license that can be found in the LICENSE file.
 
 
-/**
- * An HTML <menu> element.
- *
- * A <menu> element represents an unordered list of menu commands.
- *
- * See also:
- *
- *  * [Menu Element](https://developer.mozilla.org/en-US/docs/HTML/Element/menu) from MDN.
- *  * [Menu Element](http://www.w3.org/TR/html5/the-menu-element.html#the-menu-element) from the W3C.
- */
 /// @domName HTMLMenuElement; @docsEditable true
 class MenuElement extends Element implements Element native "*HTMLMenuElement" {
 
@@ -13402,6 +13370,10 @@ class NamedNodeMap implements JavaScriptIndexingBehavior, List<Node> native "*Na
 /// @domName Navigator; @docsEditable true
 class Navigator native "*Navigator" {
 
+  /// @domName Navigator.language; @docsEditable true
+  String get language => JS('String', '#.language || #.userLanguage', this,
+      this);
+  
   /// @domName Navigator.appCodeName; @docsEditable true
   final String appCodeName;
 
@@ -13417,9 +13389,6 @@ class Navigator native "*Navigator" {
   /// @domName Navigator.geolocation; @docsEditable true
   final Geolocation geolocation;
 
-  /// @domName Navigator.language; @docsEditable true
-  final String language;
-
   /// @domName Navigator.mimeTypes; @docsEditable true
   final DOMMimeTypeArray mimeTypes;
 
@@ -13475,6 +13444,7 @@ class Navigator native "*Navigator" {
   void _webkitGetUserMedia_1(options, NavigatorUserMediaSuccessCallback successCallback, NavigatorUserMediaErrorCallback errorCallback) native;
   @JSName('webkitGetUserMedia')
   void _webkitGetUserMedia_2(options, NavigatorUserMediaSuccessCallback successCallback) native;
+
 }
 // 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