WIP: Propagate SurfaceID up window tree hierarchy

ash/mus/bridge/wm_shell_mus.cc

Index: ash/mus/bridge/wm_shell_mus.cc
diff --git a/ash/mus/bridge/wm_shell_mus.cc b/ash/mus/bridge/wm_shell_mus.cc
index 7c720a87d6ad8e634e968596c9a8b9bbe164bea0..14e55b05560e749b9849c9b5f4c5583c15f8359d 100644
--- a/ash/mus/bridge/wm_shell_mus.cc
+++ b/ash/mus/bridge/wm_shell_mus.cc
@@ -204,7 +204,12 @@ WmRootWindowControllerMus* WmShellMus::GetRootWindowControllerWithDisplayId(
 
 WmWindow* WmShellMus::NewWindow(ui::wm::WindowType window_type,
                                 ui::LayerType layer_type) {
-  WmWindowMus* window = WmWindowMus::Get(window_tree_client()->NewWindow());
+  ui::Window* uiwindow = nullptr;
+  if (layer_type == ui::LAYER_NOT_DRAWN)
+    uiwindow = window_tree_client()->NewWindowContainer();
+  else
+    uiwindow = window_tree_client()->NewWindow();
+  WmWindowMus* window = WmWindowMus::Get(uiwindow);
   window->set_wm_window_type(window_type);
   // TODO(sky): support layer_type.
   NOTIMPLEMENTED();