Fix Dart 1.17 strong-mode warnings.

test/typed_wrapper/stream_test.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:async';
 
-import "package:async/async.dart";
 import "package:async/src/typed/stream.dart";
 import "package:test/test.dart";
 
 import '../utils.dart';
 
 void main() {
   group("with valid types, forwards", () {
     var controller;
     var wrapper;
     var emptyWrapper;
@@ skipping 220 matching lines @@
         expect(wrapper.listen(null).asFuture(), completes);
       });
     });
 
     test("map()", () {
       expect(wrapper.map((i) => i * 2).toList(),
           completion(equals([2, 4, 6, 8, 10])));
     });
 
     test("pipe()", () {
-      var consumer = new StreamController<T>();
+      var consumer = new StreamController();
       expect(wrapper.pipe(consumer), completes);
       expect(consumer.stream.toList(), completion(equals([1, 2, 3, 4, 5])));
     });
 
     test("reduce()", () {
       expect(wrapper.reduce((value, i) => value + i), completion(equals(15)));
       expect(emptyWrapper.reduce((value, i) => value + i), throwsStateError);
     });
 
     test("skipWhile()", () {
@@ skipping 330 matching lines @@
           expect(wrapper.join(" "), completion(equals("foo bar baz")));
         });
       });
 
       test("toString()", () {
         expect(wrapper.toString(), contains("Stream"));
       });
     });
   });
 }