Remove deprecated parts of dart:async.

pkg/barback/lib/src/asset_cascade.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.asset_cascade;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'asset.dart';
@@ skipping 169 matching lines @@
       // If this source was already loading, cancel the old load, since it may
       // return out-of-date contents for the asset.
       if (_loadingSources.containsKey(id)) _loadingSources[id].cancel();
 
       _loadingSources[id] =
           new CancelableFuture<Asset>(graph.provider.getAsset(id));
       _loadingSources[id].whenComplete(() {
         _loadingSources.remove(id);
       }).then((asset) {
         var controller = _sourceControllerMap[id].setAvailable(asset);
-      }).catchError((error) {
-        reportError(new AssetLoadException(id, error));
+      }).catchError((error, stack) {
+        reportError(new AssetLoadException(id, error, stack));
 
         // TODO(nweiz): propagate error information through asset nodes.
         _sourceControllerMap.remove(id).setRemoved();
       });
     }
   }
 
   /// Removes [removed] from the graph's known set of source assets.
   void removeSources(Iterable<AssetId> removed) {
     removed.forEach((id) {
@@ skipping 99 matching lines @@
 
         // Otherwise, everything is done.
         return;
       }
 
       // Process that phase and then loop onto the next.
       return future.then((_) => _process());
     });
   }
 }