diff -r 000000000000 -r 6474c204b198 widget/cocoa/nsCocoaFeatures.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widget/cocoa/nsCocoaFeatures.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,31 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 nsCocoaFeatures_h_
+#define nsCocoaFeatures_h_
+
+#include <stdint.h>
+
+class nsCocoaFeatures {
+public:
+  static int32_t OSXVersion();
+  static int32_t OSXVersionMajor();
+  static int32_t OSXVersionMinor();
+  static int32_t OSXVersionBugFix();
+  static bool OnLionOrLater();
+  static bool OnMountainLionOrLater();
+  static bool SupportCoreAnimationPlugins();
+  static bool OnMavericksOrLater();
+  static bool OnYosemiteOrLater();
+
+private:
+  static void InitializeVersionNumbers();
+
+  static int32_t mOSXVersion;
+  static int32_t mOSXVersionMajor;
+  static int32_t mOSXVersionMinor;
+  static int32_t mOSXVersionBugFix;
+};
+#endif // nsCocoaFeatures_h_