Fix build for throwsStateError: remove duplicate definitions in other tests.

utils/tests/pub/curl_client_test.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 curl_client_test;
 
 import 'dart:io';
 import 'dart:isolate';
 import 'dart:json' as json;
 import 'dart:uri';
@@ skipping 150 matching lines @@
 
     return _matcher.matches(parsed, matchState);
   }
 
   Description describe(Description description) {
     return description.add('parses to a value that ')
       .addDescriptionOf(_matcher);
   }
 }
 
-// TODO(nweiz): remove this once it's built in to unittest (issue 7922).
-/// A matcher for StateErrors.
-const isStateError = const _StateError();
-
-/// A matcher for functions that throw StateError.
-const Matcher throwsStateError =
-    const Throws(isStateError);
-
-class _StateError extends TypeMatcher {
-  const _StateError() : super("StateError");
-  bool matches(item, MatchState matchState) => item is StateError;
-}
-
 /// A matcher for HttpExceptions.
 const isHttpException = const _HttpException();
 
 /// A matcher for functions that throw HttpException.
 const Matcher throwsHttpException =
     const Throws(isHttpException);
 
 class _HttpException extends TypeMatcher {
   const _HttpException() : super("HttpException");
   bool matches(item, MatchState matchState) => item is HttpException;
@@ skipping 257 matching lines @@
   test('without following redirects', () {
     var request = new http.Request('GET', serverUrl.resolve('/redirect'));
     request.followRedirects = false;
     expect(new CurlClient().send(request).then(http.Response.fromStream)
         .then((response) {
       expect(response.statusCode, equals(302));
       expect(response.isRedirect, true);
     }), completes);
   });
 }