Stop running pub get at gclient sync time and fix build bugs

mojo/public/dart/third_party/unittest/test/missing_tick_test.dart

Index: mojo/public/dart/third_party/unittest/test/missing_tick_test.dart
diff --git a/mojo/public/dart/third_party/unittest/test/missing_tick_test.dart b/mojo/public/dart/third_party/unittest/test/missing_tick_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..81b033153206068b3f3267ca9e897721640252a1
--- /dev/null
+++ b/mojo/public/dart/third_party/unittest/test/missing_tick_test.dart
@@ -0,0 +1,27 @@
+// 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.missing_tick_test;
+
+import 'package:unittest/unittest.dart';
+
+import 'package:metatest/metatest.dart';
+
+void main() => initTests(_test);
+
+void _test(message) {
+  initMetatest(message, timeout: const Duration(seconds: 1));
+
+  expectTestResults('missing tick', () {
+    test('test that should time out', () {
+      expectAsync(() {});
+    });
+  }, [
+    {
+      'description': 'test that should time out',
+      'message': 'Test timed out after 1 seconds.',
+      'result': 'error',
+    }
+  ]);
+}