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

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

Index: mojo/public/dart/third_party/unittest/test/invalid_ops_test.dart
diff --git a/mojo/public/dart/third_party/unittest/test/invalid_ops_test.dart b/mojo/public/dart/third_party/unittest/test/invalid_ops_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..d9e05e741607d49cab008d918e0ecfb6f2423e3f
--- /dev/null
+++ b/mojo/public/dart/third_party/unittest/test/invalid_ops_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.invalid_ops_test;
+
+import 'package:unittest/unittest.dart';
+
+import 'package:metatest/metatest.dart';
+
+void main() => initTests(_test);
+
+void _test(message) {
+  initMetatest(message);
+
+  expectTestsPass('testcases immutable', () {
+    test('test', () {
+      expect(() => test('test', () {}), throwsStateError);
+      expect(() => solo_test('test', () {}), throwsStateError);
+      expect(() => group('test', () {}), throwsStateError);
+      expect(() => solo_group('test', () {}), throwsStateError);
+      expect(() => setUp(() {}), throwsStateError);
+      expect(() => tearDown(() {}), throwsStateError);
+      expect(() => runTests(), throwsStateError);
+    });
+  });
+}