diff -r 000000000000 -r 6474c204b198 xpcom/base/nsMacUtilsImpl.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/base/nsMacUtilsImpl.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,37 @@
+/* -*- Mode: C++; tab-width: 2; 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 nsMacUtilsImpl_h___
+#define nsMacUtilsImpl_h___
+
+#include "nsIMacUtils.h"
+#include "nsString.h"
+#include "mozilla/Attributes.h"
+
+class nsMacUtilsImpl MOZ_FINAL : public nsIMacUtils
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIMACUTILS
+
+  nsMacUtilsImpl() {}
+
+private:
+  ~nsMacUtilsImpl() {}
+
+  nsresult GetArchString(nsAString& archString);
+
+  // A string containing a "-" delimited list of architectures
+  // in our binary.
+  nsString mBinaryArchs;
+};
+
+// Global singleton service
+// 697BD3FD-43E5-41CE-AD5E-C339175C0818
+#define NS_MACUTILSIMPL_CID \
+ {0x697BD3FD, 0x43E5, 0x41CE, {0xAD, 0x5E, 0xC3, 0x39, 0x17, 0x5C, 0x08, 0x18}}
+#define NS_MACUTILSIMPL_CONTRACTID "@mozilla.org/xpcom/mac-utils;1"
+
+#endif /* nsMacUtilsImpl_h___ */