Re-apply "Remove unittest and matcher from the repo."

pkg/unittest/test/skipped_soloed_nested_test.dart

Index: pkg/unittest/test/skipped_soloed_nested_test.dart
diff --git a/pkg/unittest/test/skipped_soloed_nested_test.dart b/pkg/unittest/test/skipped_soloed_nested_test.dart
deleted file mode 100644
index 35d7d24e17ce677176dc8db9481b6f8d8baff288..0000000000000000000000000000000000000000
--- a/pkg/unittest/test/skipped_soloed_nested_test.dart
+++ /dev/null
@@ -1,89 +0,0 @@
-// 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 unittest.skipped_soloed_nested_test;
-
-import 'package:unittest/unittest.dart';
-
-import 'package:metatest/metatest.dart';
-
-void main() => initTests(_test);
-
-void _test(message) {
-  initMetatest(message);
-
-  expectTestResults('skipped/soloed nested groups with setup/teardown', () {
-    StringBuffer s = null;
-    setUp(() {
-      if (s == null) s = new StringBuffer();
-    });
-    test('top level', () {
-      s.write('A');
-    });
-    skip_test('skipped top level', () {
-      s.write('B');
-    });
-    skip_group('skipped top level group', () {
-      setUp(() {
-        s.write('C');
-      });
-      solo_test('skipped solo nested test', () {
-        s.write('D');
-      });
-    });
-    group('non-solo group', () {
-      setUp(() {
-        s.write('E');
-      });
-      test('in non-solo group', () {
-        s.write('F');
-      });
-      solo_test('solo_test in non-solo group', () {
-        s.write('G');
-      });
-    });
-    solo_group('solo group', () {
-      setUp(() {
-        s.write('H');
-      });
-      test('solo group non-solo test', () {
-        s.write('I');
-      });
-      solo_test('solo group solo test', () {
-        s.write('J');
-      });
-      group('nested non-solo group in solo group', () {
-        test('nested non-solo group non-solo test', () {
-          s.write('K');
-        });
-        solo_test('nested non-solo group solo test', () {
-          s.write('L');
-        });
-      });
-    });
-    solo_test('final', () {
-      expect(s.toString(), "EGHIHJHKHL");
-    });
-  }, [{
-    'description': 'non-solo group solo_test in non-solo group',
-    'result': 'pass',
-  }, {
-    'description': 'solo group solo group non-solo test',
-    'result': 'pass',
-  }, {
-    'description': 'solo group solo group solo test',
-    'result': 'pass',
-  }, {
-    'description': 'solo group nested non-solo group in solo group '
-        'nested non-solo group non-solo test',
-    'result': 'pass',
-  }, {
-    'description': 'solo group nested non-solo group in solo group '
-        'nested non-solo group solo test',
-    'result': 'pass',
-  }, {
-    'description': 'final',
-    'result': 'pass',
-  }]);
-}