Change MatchState to Map.

pkg/oauth2/test/utils.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.
 
 library utils;
 
 import 'dart:async';
 import 'dart:collection' show Queue;
 
 import 'package:http/http.dart' as http;
@@ skipping 36 matching lines @@
 
 /// A matcher for AuthorizationExceptions.
 const isAuthorizationException = const _AuthorizationException();
 
 /// A matcher for functions that throw AuthorizationException.
 const Matcher throwsAuthorizationException =
     const Throws(isAuthorizationException);
 
 class _AuthorizationException extends TypeMatcher {
   const _AuthorizationException() : super("AuthorizationException");
-  bool matches(item, MatchState matchState) =>
+  bool matches(item, Map matchState) =>
     item is oauth2.AuthorizationException;
 }
 
 /// A matcher for ExpirationExceptions.
 const isExpirationException = const _ExpirationException();
 
 /// A matcher for functions that throw ExpirationException.
 const Matcher throwsExpirationException =
     const Throws(isExpirationException);
 
 class _ExpirationException extends TypeMatcher {
   const _ExpirationException() : super("ExpirationException");
-  bool matches(item, MatchState matchState) =>
+  bool matches(item, Map matchState) =>
     item is oauth2.ExpirationException;
 }