Changed how Experimental annotation works. No longer is a constructor.

tools/dom/templates/html/impl/impl_Navigator.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 $LIBRARYNAME;
 
 $(ANNOTATIONS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 
 $if DART2JS
   @DomName('Navigator.language')
@@ skipping 14 matching lines @@
    *         ..autoplay = true
    *         ..src = Url.createObjectUrl(stream);
    *       document.body.append(video);
    *     });
    *
    * See also:
    * * [MediaStream.supported]
    */
   @DomName('Navigator.webkitGetUserMedia')
   @SupportedBrowser(SupportedBrowser.CHROME)
-  @Experimental()
+  @Experimental
   Future<LocalMediaStream> getUserMedia({bool audio: false,
       bool video: false}) {
     var completer = new Completer<LocalMediaStream>();
     var options = {
       'audio': audio,
       'video': video
     };
 $if DART2JS
     _ensureGetUserMedia();
     this._getUserMedia(convertDartToNative_Dictionary(options),
@@ skipping 24 matching lines @@
     }
   }
 
   @JSName('getUserMedia')
   void _getUserMedia(options, _NavigatorUserMediaSuccessCallback success,
       _NavigatorUserMediaErrorCallback error) native;
 $endif
 
 $!MEMBERS
 }