Remove barback from the repo.

pkg/barback/lib/src/transformer/declaring_aggregate_transform.dart

Index: pkg/barback/lib/src/transformer/declaring_aggregate_transform.dart
diff --git a/pkg/barback/lib/src/transformer/declaring_aggregate_transform.dart b/pkg/barback/lib/src/transformer/declaring_aggregate_transform.dart
deleted file mode 100644
index cfcb782b5d41a16b28c44e1de7f1b572477fbcfb..0000000000000000000000000000000000000000
--- a/pkg/barback/lib/src/transformer/declaring_aggregate_transform.dart
+++ /dev/null
@@ -1,105 +0,0 @@
-// Copyright (c) 2014, 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.transformer.declaring_aggregate_transform;
-
-import 'dart:async';
-
-import '../asset/asset_id.dart';
-import '../graph/transform_node.dart';
-import '../utils.dart';
-import 'base_transform.dart';
-
-/// A transform for [DeclaringAggregateTransformer]s that allows them to declare
-/// the ids of the outputs they'll generate without generating the concrete
-/// bodies of those outputs.
-class DeclaringAggregateTransform extends BaseTransform {
-  /// The set of output ids declared by the transformer.
-  final _outputIds = new Set<AssetId>();
-
-  /// The transform key.
-  ///
-  /// This is the key returned by [AggregateTransformer.classifyPrimary] for all
-  /// the assets in this transform.
-  final String key;
-
-  /// The package in which this transform is running.
-  final String package;
-
-  /// The stream of primary input ids that have been aggregated for this
-  /// transform.
-  ///
-  /// This is exposed as a stream so that the transformer can start working
-  /// before all its input ids are available. The stream is closed not just when
-  /// all inputs are provided, but when barback is confident no more inputs will
-  /// be forthcoming.
-  ///
-  /// A transformer may complete its `declareOutputs` method before this stream
-  /// is closed. For example, it may know that each key will only have two
-  /// inputs associated with it, and so use `transform.primaryIds.take(2)` to
-  /// access only those inputs' ids.
-  Stream<AssetId> get primaryIds => _primaryIds;
-  Stream<AssetId> _primaryIds;
-
-  /// The controller for [primaryIds].
-  ///
-  /// This is a broadcast controller so that the transform can keep
-  /// [_emittedPrimaryIds] up to date.
-  final _idController = new StreamController<AssetId>.broadcast();
-
-  /// The set of all primary input ids that have been emitted by [primaryIds].
-  final _emittedPrimaryIds = new Set<AssetId>();
-
-  DeclaringAggregateTransform._(TransformNode node)
-      : key = node.key,
-        package = node.phase.cascade.package,
-        super(node) {
-    _idController.stream.listen(_emittedPrimaryIds.add);
-    // [primaryIds] should be a non-broadcast stream.
-    _primaryIds = broadcastToSingleSubscription(_idController.stream);
-  }
-
-  /// Stores [id] as the id of an output that will be created by this
-  /// transformation when it's run.
-  ///
-  /// A transformation can declare as many assets as it wants. If
-  /// [DeclaringTransformer.declareOutputs] declares a given asset id for a
-  /// given input, [Transformer.apply] should emit the corresponding asset as
-  /// well.
-  void declareOutput(AssetId id) {
-    // TODO(nweiz): This should immediately throw if an output with that ID
-    // has already been declared by this transformer.
-    _outputIds.add(id);
-  }
-
-  void consumePrimary(AssetId id) {
-    if (!_emittedPrimaryIds.contains(id)) {
-      throw new StateError(
-          "$id can't be consumed because it's not a primary input.");
-    }
-
-    super.consumePrimary(id);
-  }
-}
-
-/// The controller for [DeclaringAggregateTransform].
-class DeclaringAggregateTransformController extends BaseTransformController {
-  DeclaringAggregateTransform get transform => super.transform;
-
-  /// The set of ids that the transformer declares it will emit.
-  Set<AssetId> get outputIds => transform._outputIds;
-
-  bool get isDone => transform._idController.isClosed;
-
-  DeclaringAggregateTransformController(TransformNode node)
-      : super(new DeclaringAggregateTransform._(node));
-
-  /// Adds a primary input id to the [DeclaringAggregateTransform.primaryIds]
-  /// stream.
-  void addId(AssetId id) => transform._idController.add(id);
-
-  void done() {
-    transform._idController.close();
-  }
-}