Update to latest analyzer

tool/input_sdk/lib/async/future_impl.dart

 // 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 dart.async;
 
 /** The onValue and onError handlers return either a value or a future */
 typedef dynamic _FutureOnValue<T>(T value);
 /** Test used by [Future.catchError] to handle skip some errors. */
 typedef bool _FutureErrorTest(var error);
@@ skipping 184 matching lines @@
   set _isChained(bool value) {
     if (value) {
       assert(!_isComplete);
       _state = _CHAINED;
     } else {
       assert(_isChained);
       _state = _INCOMPLETE;
     }
   }
 
-  Future then(f(T value), { Function onError }) {
-    _Future result = new _Future();
+  Future/*<S>*/ then/*<S>*/(/*=S*/ f(T value), { Function onError }) {
+    _Future/*<S>*/ result = new _Future();
     if (!identical(result._zone, _ROOT_ZONE)) {
       f = result._zone.registerUnaryCallback(f);
       if (onError != null) {
         onError = _registerErrorHandler(onError, result._zone);
       }
     }
     _addListener(new _FutureListener.then(result, f, onError));
     return result;
   }
 
@@ skipping 425 matching lines @@
       }
     }, onError: (e, s) {
       if (timer.isActive) {
         timer.cancel();
         result._completeError(e, s);
       }
     });
     return result;
   }
 }