chromeos: converts PanelLayoutManager 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 b8e06c2d26e78aaa86088e01a810dd3ec3227b69..904fc145c1ad7b5926a48e0b54472f209f586bd5 100644
--- a/ash/wm/workspace/workspace_layout_manager.cc
+++ b/ash/wm/workspace/workspace_layout_manager.cc
@@ -215,9 +215,8 @@ void WorkspaceLayoutManager::OnWindowPropertyChanged(aura::Window* window,
   if (key == aura::client::kAlwaysOnTopKey) {
     if (window->GetProperty(aura::client::kAlwaysOnTopKey)) {
       aura::Window* container =
-          root_window_controller_->always_on_top_controller()
-              ->GetContainer(WmWindow::Get(window))
-              ->aura_window();
+          root_window_controller_->always_on_top_controller()->GetContainer(
+              window);
       if (window->parent() != container)
         container->AddChild(window);
     }