Matthias Clasen authored Dec 15, 2011 and Colin Walters committed Dec 20, 2011

GTK+ also exports window-specific actions, by putting the object path
for the exported action group in the _DBUS_OBJECT_PATH X property.
We add this action group to the app's muxer with a 'win' prefix,
since that is what the exported menu expects. Whenever the focus
window changes, we update the window-specific actions of its
application, and emit notify::action-group to cause the app
menu to be updated.