diff -r 000000000000 -r 6474c204b198 hal/HalScreenConfiguration.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hal/HalScreenConfiguration.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,20 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_HalScreenConfiguration_h
+#define mozilla_HalScreenConfiguration_h
+
+#include "mozilla/Observer.h"
+
+namespace mozilla {
+namespace hal {
+struct ScreenConfiguration;
+typedef Observer<ScreenConfiguration> ScreenConfigurationObserver;
+} // namespace hal
+} // namespace mozilla
+
+#endif  // mozilla_HalScreenConfiguration_h
+