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

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

Index: mojo/public/dart/third_party/unittest/test/late_exception_test.dart
diff --git a/mojo/public/dart/third_party/unittest/test/late_exception_test.dart b/mojo/public/dart/third_party/unittest/test/late_exception_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..94ad30b3fdd3f832c322b45ff410c0e9b43b27d3
--- /dev/null
+++ b/mojo/public/dart/third_party/unittest/test/late_exception_test.dart
@@ -0,0 +1,37 @@
+// 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.late_exception_test;
+
+import 'dart:async';
+
+import 'package:metatest/metatest.dart';
+import 'package:unittest/unittest.dart';
+
+void main() => initTests(_test);
+
+void _test(message) {
+  initMetatest(message);
+
+  expectTestResults('late exception test', () {
+    var f;
+    test('testOne', () {
+      f = expectAsync(() {});
+      new Future.sync(f);
+    });
+    test('testTwo', () {
+      new Future.sync(expectAsync(() {
+        f();
+      }));
+    });
+  }, [
+    {
+      'description': 'testOne',
+      'message': 'Callback called (2) after test case testOne had already been '
+          'marked as pass.',
+      'result': 'error',
+    },
+    {'description': 'testTwo', 'result': 'pass',}
+  ]);
+}