diff -r 000000000000 -r 6474c204b198 widget/windows/nsIdleServiceWin.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widget/windows/nsIdleServiceWin.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim:expandtab:shiftwidth=4:tabstop=4:
+ */
+/* 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/. */
+
+#include "nsIdleServiceWin.h"
+#include <windows.h>
+
+NS_IMPL_ISUPPORTS_INHERITED0(nsIdleServiceWin, nsIdleService)
+
+bool
+nsIdleServiceWin::PollIdleTime(uint32_t *aIdleTime)
+{
+    LASTINPUTINFO inputInfo;
+    inputInfo.cbSize = sizeof(inputInfo);
+    if (!::GetLastInputInfo(&inputInfo))
+        return false;
+
+    *aIdleTime = SAFE_COMPARE_EVEN_WITH_WRAPPING(GetTickCount(), inputInfo.dwTime);
+
+    return true;
+}
+
+bool
+nsIdleServiceWin::UsePollMode()
+{
+    return true;
+}