now able to set the layer stack on a DisplayDevice

Change-Id: Ia9691cf221b9444c243eb468d9e276a30e600b6b
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 1f9d694..1c15c82 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -857,7 +857,7 @@
                     const DisplayDeviceState& state(curr[i]);
                     if (state.layerStack != draw[i].layerStack) {
                         const sp<DisplayDevice>& disp(getDisplayDevice(state.id));
-                        //disp->setLayerStack(state.layerStack); // FIXME: set layer stack
+                        disp->setLayerStack(state.layerStack);
                     }
                     if (curr[i].orientation != draw[i].orientation) {
                         const sp<DisplayDevice>& disp(getDisplayDevice(state.id));