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

mojo/public/dart/third_party/test/bin/test.dart

Index: mojo/public/dart/third_party/test/bin/test.dart
diff --git a/mojo/public/dart/third_party/test/bin/test.dart b/mojo/public/dart/third_party/test/bin/test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..0b40282a606bc05d57acede2d8ae0eaa798a1e43
--- /dev/null
+++ b/mojo/public/dart/third_party/test/bin/test.dart
@@ -0,0 +1,5 @@
+// Copyright (c) 2015, 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.
+
+export 'package:test/src/executable.dart';