Remove the wrapStream workaround for issue 8310.

utils/tests/pub/test_pub.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.
 
 /// Test infrastructure for testing pub. Unlike typical unit tests, most pub
 /// tests are integration tests that stage some stuff on the file system, run
 /// pub, and then validate the results. This library provides an API to build
 /// tests like that.
 library test_pub;
 
@@ skipping 1297 matching lines @@
   /// Whether the process is expected to terminate at this point.
   bool _endExpected = false;
 
   /// Wraps a [Process] [Future] in a scheduled process.
   ScheduledProcess(this.name, Future<PubProcess> process)
     : _processFuture = process {
     var pairFuture = process.then((p) {
       _process = p;
 
       byteStreamToLines(stream) {
-        var handledErrors = wrapStream(stream.handleError((e) {
+        return streamToLines(new ByteStream(stream.handleError((e) {
           registerException(e.error, e.stackTrace);
-        }));
-        return streamToLines(new ByteStream(handledErrors).toStringStream());
+        })).toStringStream());
       }
 
       var stdoutTee = tee(byteStreamToLines(p.stdout));
       var stdoutPair = streamWithSubscription(stdoutTee.last);
       _stdout = stdoutPair.first;
       _stdoutSubscription = stdoutPair.last;
 
       var stderrTee = tee(byteStreamToLines(p.stderr));
       var stderrPair = streamWithSubscription(stderrTee.last);
       _stderr = stderrPair.first;
@@ skipping 302 matching lines @@
 /// calling [completion] is unnecessary.
 void expectLater(Future actual, matcher, {String reason,
     FailureHandler failureHandler, bool verbose: false}) {
   _schedule((_) {
     return actual.then((value) {
       expect(value, matcher, reason: reason, failureHandler: failureHandler,
           verbose: false);
     });
   });
 }