Adapt streams for additional stackTrace argument.

pkg/barback/lib/src/stream_replayer.dart

Index: pkg/barback/lib/src/stream_replayer.dart
diff --git a/pkg/barback/lib/src/stream_replayer.dart b/pkg/barback/lib/src/stream_replayer.dart
index 177e13d609f6cc9bb0fafa00ec85ae8d4a8007b6..67e75fab1883943f1ec4b54b8e201174528430f2 100644
--- a/pkg/barback/lib/src/stream_replayer.dart
+++ b/pkg/barback/lib/src/stream_replayer.dart
@@ -34,10 +34,10 @@ class StreamReplayer<T> {
       for (var controller in _controllers) {
         controller.add(data);
       }
-    }, onError: (error) {
+    }, onError: (error, [StackTrace stackTrace]) {

[nweiz, 2013/10/07 18:49:51]

[_buffer] now needs to track the stack trace along with errors. It should
probably be an Either<T, Pair<dynamic, StackTrace>> now.

[floitsch, 2013/10/10 14:22:52]

Done.

       _buffer.add(new Either<T, dynamic>.withSecond(error));
       for (var controller in _controllers) {
-        controller.addError(error);
+        controller.addError(error, stackTrace);
       }
     }, onDone: () {
       _isClosed = true;