Remove StreamController.broadcast.

utils/pub/error_group.dart

Index: utils/pub/error_group.dart
diff --git a/utils/pub/error_group.dart b/utils/pub/error_group.dart
index b5f8f8e9ea5fc1f9804b36411473a215e6238fae..d268d61f626540a5ed0a298bba3d6b2e377264f0 100644
--- a/utils/pub/error_group.dart
+++ b/utils/pub/error_group.dart
@@ -225,6 +225,10 @@ class _ErrorGroupStream extends Stream {
   /// The underlying [StreamController] for [this].
   final StreamController _controller;
 
+  /// The controller's [Stream]. May be different than `_controller.stream` if
+  /// the wrapped stream is a broadcasting stream.
+  Stream _stream;
+
   /// The [StreamSubscription] that connects the wrapped [Stream] to
   /// [_controller].
   StreamSubscription _subscription;
@@ -235,9 +239,10 @@ class _ErrorGroupStream extends Stream {
   /// Creates a new [_ErrorGroupFuture] that's a child of [_group] and wraps
   /// [inner].
   _ErrorGroupStream(this._group, Stream inner)
-    : _controller = inner.isBroadcast ?
-          new StreamController.broadcast() :
-          new StreamController() {
+    : _controller = new StreamController() {
+    this.stream = isBroadcast
+        ? _controller.stream.asBroadcastStream()
+        : _controller.stream;
     _subscription = inner.listen((v) {
       _controller.add(v);
     }, onError: (e) {