Fix a few breakages with Pub's oauth2 test.

utils/pub/utils.dart

Index: utils/pub/utils.dart
diff --git a/utils/pub/utils.dart b/utils/pub/utils.dart
index 7e91b43801528ccd11ba72d2695f1b420b1efd0b..8617f2071bb24ef45801dbd702d3c21b4b967e1b 100644
--- a/utils/pub/utils.dart
+++ b/utils/pub/utils.dart
@@ -137,9 +137,9 @@ Future streamFirst(Stream stream) {
 /// Returns a wrapped version of [stream] along with a [StreamSubscription] that
 /// can be used to control the wrapped stream.
 Pair<Stream, StreamSubscription> streamWithSubscription(Stream stream) {
-  var controller = stream.isSingleSubscription ?
-      new StreamController() :
-      new StreamController.multiSubscription();
+  var controller = stream.isBroadcast ?
+      new StreamController.broadcast() :
+      new StreamController();
   var subscription = stream.listen(controller.add,
       onError: controller.signalError,
       onDone: controller.close);