Makes functions in container_finder take aura::Window

ash/mus/top_level_window_factory.cc

Index: ash/mus/top_level_window_factory.cc
diff --git a/ash/mus/top_level_window_factory.cc b/ash/mus/top_level_window_factory.cc
index 0a921198c97961c73e3c0fe6ccb87806d5fd5fa9..7fa50bdbf485eed84c23fccffd5e70ab658564d0 100644
--- a/ash/mus/top_level_window_factory.cc
+++ b/ash/mus/top_level_window_factory.cc
@@ -187,9 +187,7 @@ aura::Window* CreateAndParentTopLevelWindowInRoot(
                   .bounds()
                   .OffsetFromOrigin();
     gfx::Rect bounds_in_screen(origin, bounds.size());
-    ash::wm::GetDefaultParent(WmWindow::Get(window), bounds_in_screen)
-        ->aura_window()
-        ->AddChild(window);
+    ash::wm::GetDefaultParent(window, bounds_in_screen)->AddChild(window);
   }
   return window;
 }