Aura: Remove overlapping window mode

ash/wm/toplevel_layout_manager.h

Index: ash/wm/toplevel_layout_manager.h
diff --git a/ash/wm/toplevel_layout_manager.h b/ash/wm/toplevel_layout_manager.h
index a459ccc38e867459dd966fa8a3288f9200e8100b..faf6d5fbcf8b4ad2ed703f50123e5f87320d4f7d 100644
--- a/ash/wm/toplevel_layout_manager.h
+++ b/ash/wm/toplevel_layout_manager.h
@@ -23,6 +23,9 @@ class ShelfLayoutManager;
 // compact window mode is not enabled. It is intended to implement the simplest
 // possible window management code. If you have a more complex window mode
 // please implement a new LayoutManager for it.
+//
+// TODO(jamescook): If we're happy with managed window mode, this class and
+// its tests can be deleted.
 class ASH_EXPORT ToplevelLayoutManager : public BaseLayoutManager {
  public:
   ToplevelLayoutManager();