Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/args/args.dart

Index: observatory_pub_packages/args/args.dart
===================================================================
--- observatory_pub_packages/args/args.dart	(revision 0)
+++ observatory_pub_packages/args/args.dart	(working copy)
@@ -0,0 +1,9 @@
+// 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 args;
+
+export 'src/arg_parser.dart';
+export 'src/arg_results.dart' hide newArgResults;
+export 'src/option.dart' hide newOption;