Add Supported class to dart:html

tools/dom/scripts/systemhtml.py

 #!/usr/bin/python
 # 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.
 
 """This module provides shared functionality for the system to generate
 Dart:html APIs from the IDL database."""
 
 import emitter
 import monitored
@@ skipping 351 matching lines @@
   'SVGFETileElement',
   'SVGFETurbulenceElement',
   'SVGFilterElement',
   'SVGForeignObjectElement',
   'SVGSetElement',
 ]
 
 js_support_checks = dict({
     'AudioContext': "JS('bool', '!!(window.AudioContext ||"
         " window.webkitAudioContext)')",
-    'ArrayBuffer': "JS('bool', 'typeof window.ArrayBuffer != \"undefined\"')",
     'Crypto':
         "JS('bool', '!!(window.crypto && window.crypto.getRandomValues)')",
     'Database': "JS('bool', '!!(window.openDatabase)')",
     'DOMApplicationCache': "JS('bool', '!!(window.applicationCache)')",
     'DOMFileSystem': "JS('bool', '!!(window.webkitRequestFileSystem)')",
     'FormData': "JS('bool', '!!(window.FormData)')",
     'HashChangeEvent': "Device.isEventTypeSupported('HashChangeEvent')",
     'HTMLShadowElement': ElemSupportStr('shadow'),
     'MediaStreamEvent': "Device.isEventTypeSupported('MediaStreamEvent')",
     'MediaStreamTrackEvent': "Device.isEventTypeSupported('MediaStreamTrackEvent')",
@@ skipping 771 matching lines @@
     for library_name in libraries:
       self._libraries[library_name] = DartLibrary(
           library_name, template_loader, library_type, output_dir)
 
   def AddFile(self, basename, library_name, path):
     self._libraries[library_name].AddFile(path)
 
   def Emit(self, emitter, auxiliary_dir):
     for lib in self._libraries.values():
       lib.Emit(emitter, auxiliary_dir)