Rip out dart:io from pkg/http wherever possible.

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:convert';
 import 'dart:io';
 
-import 'package:http/src/byte_stream.dart';
+import 'package:http/http.dart';
 import 'package:http/src/utils.dart';
 import 'package:unittest/unittest.dart';
 
 /// The current server instance.
 HttpServer _server;
 
 /// The URL for the current server instance.
 Uri get serverUrl => Uri.parse('http://localhost:${_server.port}');
 
 /// A dummy URL for constructing requests that won't be sent.
@@ skipping 145 matching lines @@
 
     return _matcher.matches(parsed, matchState);
   }
 
   Description describe(Description description) {
     return description.add('parses to a value that ')
       .addDescriptionOf(_matcher);
   }
 }
 
-/// 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, Map matchState) => item is HttpException;
-}
+Matcher get throwsClientException =>
+    throwsA(new isInstanceOf<ClientException>());
 
 /// A matcher for RedirectLimitExceededExceptions.
 const isRedirectLimitExceededException =
     const _RedirectLimitExceededException();
 
 /// A matcher for functions that throw RedirectLimitExceededException.
 const Matcher throwsRedirectLimitExceededException =
     const Throws(isRedirectLimitExceededException);
 
 class _RedirectLimitExceededException extends TypeMatcher {
   const _RedirectLimitExceededException() :
       super("RedirectLimitExceededException");
 
   bool matches(item, Map matchState) =>
     item is RedirectException && item.message == "Redirect limit exceeded";
 }
 
 /// A matcher for SocketExceptions.
 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;
 }