diff -r 000000000000 -r 6474c204b198 widget/gtk/nsIdleServiceGTK.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widget/gtk/nsIdleServiceGTK.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,52 @@
+/* -*- 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/. */
+
+#ifndef nsIdleServiceGTK_h__
+#define nsIdleServiceGTK_h__
+
+#include "nsIdleService.h"
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <gdk/gdkx.h>
+
+typedef struct {
+    Window window;              // Screen saver window
+    int state;                  // ScreenSaver(Off,On,Disabled)
+    int kind;                   // ScreenSaver(Blanked,Internal,External)
+    unsigned long til_or_since; // milliseconds since/til screensaver kicks in
+    unsigned long idle;         // milliseconds idle
+    unsigned long event_mask;   // event stuff
+} XScreenSaverInfo;
+
+class nsIdleServiceGTK : public nsIdleService
+{
+public:
+    NS_DECL_ISUPPORTS_INHERITED
+
+    bool PollIdleTime(uint32_t* aIdleTime);
+
+    static already_AddRefed<nsIdleServiceGTK> GetInstance()
+    {
+        nsRefPtr<nsIdleServiceGTK> idleService =
+            nsIdleService::GetInstance().downcast<nsIdleServiceGTK>();
+        if (!idleService) {
+            idleService = new nsIdleServiceGTK();
+        }
+
+        return idleService.forget();
+    }
+
+private:
+    ~nsIdleServiceGTK();
+    XScreenSaverInfo* mXssInfo;
+
+protected:
+    nsIdleServiceGTK();
+    bool UsePollMode();
+};
+
+#endif // nsIdleServiceGTK_h__