Roll forward commits r33138, r33135, and r33134.

pkg/barback/lib/src/group_runner.dart

 // Copyright (c) 2013, 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.
 
 library barback.group_runner;
 
 import 'dart:async';
 
 import 'asset_cascade.dart';
 import 'asset_node.dart';
+import 'asset_node_set.dart';

[Bob Nystrom, 2014/03/06 21:29:36]

Is this needed?

[nweiz, 2014/03/06 22:24:28]

Good eye. Nope.

 import 'log.dart';
 import 'phase.dart';
 import 'stream_pool.dart';
 import 'transformer_group.dart';
 
 /// A class that processes all of the phases in a single transformer group.
 ///
 /// A group takes many inputs, processes them, and emits many outputs.
 class GroupRunner {
   /// The group this runner runs.
@@ skipping 61 matching lines @@
     _phases.first.addInput(node);
   }
 
   /// Removes this group and all sub-phases within it.
   void remove() {
     _phases.first.remove();
   }
 
   String toString() => "group in phase $_location for $_group";
 }