Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/matcher/matcher.dart

Index: observatory_pub_packages/matcher/matcher.dart
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--- observatory_pub_packages/matcher/matcher.dart	(revision 0)
+++ observatory_pub_packages/matcher/matcher.dart	(working copy)
@@ -0,0 +1,22 @@
+// 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.
+
+/// Support for specifying test expectations, such as for unit tests.
+library matcher;
+
+export 'src/core_matchers.dart';
+export 'src/description.dart';
+export 'src/error_matchers.dart';
+export 'src/expect.dart';
+export 'src/future_matchers.dart';
+export 'src/interfaces.dart';
+export 'src/iterable_matchers.dart';
+export 'src/map_matchers.dart';
+export 'src/numeric_matchers.dart';
+export 'src/operator_matchers.dart';
+export 'src/prints_matcher.dart';
+export 'src/string_matchers.dart';
+export 'src/throws_matcher.dart';
+export 'src/throws_matchers.dart';
+export 'src/util.dart';