class ChromeLocation extends ChromeApi {
 static final JsObject _location = chrome['location'];

 ChromeLocation._();

 bool get available => _location != null;

 /**
  * Starts a location watching request. If there is another location watching
  * request with the same name (or no name if none is specified), it will be
  * cancelled and replaced by this request.
  * [name]: Optional name to identify this request. Defaults to the empty
  * string.
  * [requestInfo]: Optional parameters for this request.
  */
 void watchLocation(String name, WatchLocationRequestInfo requestInfo) {
   if (_location == null) _throwNotAvailable();

   _location.callMethod('watchLocation', [name, jsify(requestInfo)]);
 }

 /**
  * Ends a location watching request.
  * [name]: Optional name to identify the request to remove. Defaults to the
  * empty string.
  */
 void clearWatch(String name) {
   if (_location == null) _throwNotAvailable();

   _location.callMethod('clearWatch', [name]);
 }

 Stream<Location> get onLocationUpdate => _onLocationUpdate.stream;

 final ChromeStreamController<Location> _onLocationUpdate =
     new ChromeStreamController<Location>.oneArg(_location, 'onLocationUpdate', _createLocation);

 Stream<String> get onLocationError => _onLocationError.stream;

 final ChromeStreamController<String> _onLocationError =
     new ChromeStreamController<String>.oneArg(_location, 'onLocationError', selfConverter);

 void _throwNotAvailable() {
   throw new UnsupportedError("'chrome.location' is not available");
 }
}