Revise barback logging patch.

pkg/barback/lib/src/transform_node.dart

Index: pkg/barback/lib/src/transform_node.dart
diff --git a/pkg/barback/lib/src/transform_node.dart b/pkg/barback/lib/src/transform_node.dart
index aa77d72a401690bf945173f81380f11b8cbb78d7..1ef19198b1c654f5c5ee2d7847eb16627850a805 100644
--- a/pkg/barback/lib/src/transform_node.dart
+++ b/pkg/barback/lib/src/transform_node.dart
@@ -12,8 +12,8 @@ import 'asset.dart';
 import 'asset_id.dart';
 import 'asset_node.dart';
 import 'asset_set.dart';
-import 'barback_logger.dart';
 import 'errors.dart';
+import 'log.dart';
 import 'phase.dart';
 import 'transform.dart';
 import 'transformer.dart';
@@ -218,7 +218,6 @@ class TransformNode {
   void _log(AssetId asset, LogLevel level, String message, Span span) {
     // If the log isn't already associated with an asset, use the primary.
     if (asset == null) asset = primary.id;
-    var info = new TransformInfo(transformer, primary.id);
     var entry = new LogEntry(info, asset, level, message, span);
     _onLogController.add(entry);
   }