Pass logs through transformer groups.

pkg/barback/lib/src/phase.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.phase;
 
 import 'dart:async';
 
 import 'asset_cascade.dart';
 import 'asset_id.dart';
@@ skipping 98 matching lines @@
   }
 
   // TODO(nweiz): Rather than passing the cascade and the phase everywhere,
   // create an interface that just exposes [getInput]. Emit errors via
   // [AssetNode]s.
   Phase(this.cascade, Iterable transformers)
       : _transformers = transformers.where((op) => op is Transformer).toSet() {
     _onDirtyPool.add(_onDirtyController.stream);
 
     for (var group in transformers.where((op) => op is TransformerGroup)) {
-      _groups[group] = new GroupRunner(cascade, group);
-      _onDirtyPool.add(_groups[group].onDirty);
+      var runner = new GroupRunner(cascade, group);
+      _groups[group] = runner;
+      _onDirtyPool.add(runner.onDirty);
+      _onLogPool.add(runner.onLog);
     }
   }
 
   /// Adds a new asset as an input for this phase.
   ///
   /// [node] doesn't have to be [AssetState.AVAILABLE]. Once it is, the phase
   /// will automatically begin determining which transforms can consume it as a
   /// primary input. The transforms themselves won't be applied until [process]
   /// is called, however.
   ///
@@ skipping 68 matching lines @@
         .toSet();
     var oldGroups = _groups.keys.toSet();
     for (var removed in oldGroups.difference(newGroups)) {
       _groups.remove(removed).remove();
     }
 
     for (var added in newGroups.difference(oldGroups)) {
       var runner = new GroupRunner(cascade, added);
       _groups[added] = runner;
       _onDirtyPool.add(runner.onDirty);
+      _onLogPool.add(runner.onLog);
       for (var input in _inputs.values) {
         runner.addInput(input.input);
       }
     }
 
     for (var forwarder in _forwarders.values) {
       forwarder.numChannels = _groups.length + 1;
     }
   }
 
@@ skipping 84 matching lines @@
       _outputs[asset.id].add(asset);
     } else {
       _outputs[asset.id] = new PhaseOutput(this, asset);
       _outputs[asset.id].onAsset.listen((output) {
         if (_next != null) _next.addInput(output);
       }, onDone: () => _outputs.remove(asset.id));
       if (_next != null) _next.addInput(_outputs[asset.id].output);
     }
   }
 }