Remove barback from the repo.

pkg/barback/lib/src/build_result.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.build_result;
-
-import 'errors.dart';
-import 'utils.dart';
-
-/// An event indicating that the cascade has finished building all assets.
-///
-/// A build can end either in success or failure. If there were no errors during
-/// the build, it's considered to be a success; any errors render it a failure,
-/// although individual assets may still have built successfully.
-class BuildResult {
-  // TODO(rnystrom): Revise how to track error results. Errors can come from
-  // both logs and exceptions. Accumulating them is likely slow and a waste of
-  // memory. If we do want to accumulate them, we should at least unify them
-  // in a single collection (probably of log entries).
-  /// All errors that were thrown during the build.
-  final Set<BarbackException> errors;
-
-  /// `true` if the build succeeded.
-  bool get succeeded => errors.isEmpty;
-
-  BuildResult(Iterable<BarbackException> errors)
-      : errors = flattenAggregateExceptions(errors).toSet();
-
-  /// Creates a build result indicating a successful build.
-  ///
-  /// This equivalent to a build result with no errors.
-  BuildResult.success()
-      : this([]);
-
-  /// Creates a single [BuildResult] that contains all of the errors of
-  /// [results].
-  factory BuildResult.aggregate(Iterable<BuildResult> results) {
-    var errors = unionAll(results.map((result) => result.errors));
-    return new BuildResult(errors);
-  }
-
-  String toString() {
-    if (succeeded) return "success";
-
-    return "errors:\n" + errors.map((error) {
-      var stackTrace = null;
-      if (error is TransformerException || error is AssetLoadException) {
-        stackTrace = error.stackTrace.terse;
-      }
-
-      var msg = new StringBuffer();
-      msg.write(prefixLines(error.toString()));
-      if (stackTrace != null) {
-        msg.write("\n\n");
-        msg.write("Stack chain:\n");
-        msg.write(prefixLines(stackTrace.toString()));
-      }
-      return msg.toString();
-    }).join("\n\n");
-  }
-}