Add missing newline after Actual value in fail message.

pkg/http/test/utils.dart

 // Copyright (c) 2013, 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 test_utils;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:json' as json;
 
@@ skipping 126 matching lines @@
     }
   }
 
   return lines.join('\n');
 }
 
 /// A matcher that matches JSON that parses to a value that matches the inner
 /// matcher.
 Matcher parse(matcher) => new _Parse(matcher);
 
-class _Parse extends BaseMatcher {
+class _Parse extends Matcher {
   final Matcher _matcher;
 
   _Parse(this._matcher);
 
   bool matches(item, Map matchState) {
     if (item is! String) return false;
 
     var parsed;
     try {
       parsed = json.parse(item);
@@ skipping 42 matching lines @@
 const isSocketException = const _SocketException();
 
 /// A matcher for functions that throw SocketException.
 const Matcher throwsSocketException =
     const Throws(isSocketException);
 
 class _SocketException extends TypeMatcher {
   const _SocketException() : super("SocketException");
   bool matches(item, Map matchState) => item is SocketException;
 }