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

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

Index: mojo/public/dart/third_party/unittest/test/excess_callback_test.dart
diff --git a/mojo/public/dart/third_party/unittest/test/excess_callback_test.dart b/mojo/public/dart/third_party/unittest/test/excess_callback_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..2679d17e202d0b706cb35b201c02d6034c6dcbfb
--- /dev/null
+++ b/mojo/public/dart/third_party/unittest/test/excess_callback_test.dart
@@ -0,0 +1,42 @@
+// 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.excess_callback_test;
+
+import 'dart:async';
+
+import 'package:metatest/metatest.dart';
+import 'package:unittest/unittest.dart';
+
+void main() => initTests(_test);
+
+void _test(message) {
+  initMetatest(message);
+
+  var count = 0;
+
+  expectTestResults('excess callback test', () {
+    test('test', () {
+      var _callback0 = expectAsync(() => ++count);
+      var _callback1 = expectAsync(() => ++count);
+      var _callback2 = expectAsync(() {
+        _callback1();
+        _callback1();
+        _callback0();
+      });
+      new Future.sync(_callback2);
+    });
+
+    test('verify count', () {
+      expect(count, 1);
+    });
+  }, [
+    {
+      'description': 'test',
+      'message': 'Callback called more times than expected (1).',
+      'result': 'fail'
+    },
+    {'description': 'verify count', 'result': 'pass',}
+  ]);
+}