Comment 2 for bug 1224202

StacktraceTop:
 gcm_prefs_device_changed_cb (device=0x7f389c00a780, prefs=0x26ef990) at cc-color-panel.c:1881
 _g_closure_invoke_va (closure=0x3fb3d10, return_value=0x0, instance=0x7f389c00a780, args=0x7fffba60d818, n_params=0, param_types=0x0) at /build/buildd/glib2.0-2.37.7/./gobject/gclosure.c:840
 g_signal_emit_valist (instance=0x7f389c00a780, signal_id=<optimized out>, detail=<optimized out>, var_args=var_args@entry=0x7fffba60d818) at /build/buildd/glib2.0-2.37.7/./gobject/gsignal.c:3238
 g_signal_emit (instance=instance@entry=0x7f389c00a780, signal_id=<optimized out>, detail=detail@entry=0) at /build/buildd/glib2.0-2.37.7/./gobject/gsignal.c:3386
 cd_device_dbus_signal_cb (proxy=<optimized out>, sender_name=<optimized out>, signal_name=0x4253d40 "Changed", parameters=<optimized out>, device=0x7f389c00a780) at cd-device.c:680