Roll to pickup pool changes

packages/barback/lib/src/asset/asset_node_set.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.asset_node_set;
 
 import 'package:collection/collection.dart';
 
 import 'asset_id.dart';
 import 'asset_node.dart';
 
 /// A set of [AssetNode]s that automatically ensures that nodes are removed from
 /// the set as soon as they're marked as [AssetState.REMOVED].
 ///
 /// Asset nodes may be accessed by their ids. This means that only one node with
 /// a given id may be stored in the set at a time.
 class AssetNodeSet extends DelegatingSet<AssetNode> {
   // TODO(nweiz): Use DelegatingMapSet when issue 18705 is fixed.
   /// A map from asset ids to assets in the set.
   final _assetsById = new Map<AssetId, AssetNode>();
 
-  AssetNodeSet()
-      : super(new Set());
+  AssetNodeSet() : super(new Set());
 
   /// Returns the asset node in the set with [id], or `null` if none exists.
   AssetNode operator [](AssetId id) => _assetsById[id];
 
   bool add(AssetNode node) {
     if (node.state.isRemoved) return false;
     node.whenRemoved(() {
       super.remove(node);
       _assetsById.remove(node.id);
     });
     _assetsById[node.id] = node;
     return super.add(node);
   }
 
   /// Returns whether an asset node with the given [id] is in the set.
   bool containsId(AssetId id) => _assetsById.containsKey(id);
 
   void addAll(Iterable<AssetNode> nodes) => nodes.forEach(add);
-}
+}