Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/barback/src/log.dart

Index: observatory_pub_packages/barback/src/log.dart
===================================================================
--- observatory_pub_packages/barback/src/log.dart	(revision 0)
+++ observatory_pub_packages/barback/src/log.dart	(working copy)
@@ -0,0 +1,41 @@
+// 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.log;
+
+import 'package:source_span/source_span.dart';
+
+import 'asset/asset_id.dart';
+import 'errors.dart';
+
+/// The severity of a logged message.
+class LogLevel {
+  static const INFO = const LogLevel("Info");
+  static const FINE = const LogLevel("Fine");
+  static const WARNING = const LogLevel("Warning");
+  static const ERROR = const LogLevel("Error");
+
+  final String name;
+  const LogLevel(this.name);
+
+  String toString() => name;
+}
+
+/// One message logged during a transform.
+class LogEntry {
+  /// The transform that logged the message.
+  final TransformInfo transform;
+
+  /// The asset that the message is associated with.
+  final AssetId assetId;
+
+  final LogLevel level;
+  final String message;
+
+  /// The location that the message pertains to or null if not associated with
+  /// a [SourceSpan].
+  final SourceSpan span;
+
+  LogEntry(this.transform, this.assetId, this.level, this.message, this.span);
+}