chromeos: converts WindowState to aura::Window

ash/wm/workspace/workspace_layout_manager.cc

Index: ash/wm/workspace/workspace_layout_manager.cc
diff --git a/ash/wm/workspace/workspace_layout_manager.cc b/ash/wm/workspace/workspace_layout_manager.cc
index 0c3dc981a81349903f7b4feb8736d61fbf6f7ca8..b861681442c95591faaf5725add6456bc699297d 100644
--- a/ash/wm/workspace/workspace_layout_manager.cc
+++ b/ash/wm/workspace/workspace_layout_manager.cc
@@ -401,7 +401,7 @@ void WorkspaceLayoutManager::UpdateAlwaysOnTop(aura::Window* window_on_top) {
   for (aura::Window* window : windows) {
     wm::WindowState* window_state = wm::GetWindowState(window);
     if (window_on_top)
-      window_state->DisableAlwaysOnTop(WmWindow::Get(window_on_top));
+      window_state->DisableAlwaysOnTop(window_on_top);
     else
       window_state->RestoreAlwaysOnTop();
   }