aura: Remove layerless windows.

ui/views/widget/widget.h

Index: ui/views/widget/widget.h
diff --git a/ui/views/widget/widget.h b/ui/views/widget/widget.h
index 2f6030bd99a397cdf3ff12422f7a40f50d96f0ee..c6b963779204c164412e90dbc19f9eab16feef80 100644
--- a/ui/views/widget/widget.h
+++ b/ui/views/widget/widget.h
@@ -13,7 +13,6 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/scoped_observer.h"
-#include "ui/aura/window_layer_type.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/events/event_source.h"
 #include "ui/gfx/geometry/rect.h"
@@ -249,8 +248,8 @@ class VIEWS_EXPORT Widget : public internal::NativeWidgetDelegate,
     // rid of NW subclasses and do this all via message handling.
     DesktopWindowTreeHost* desktop_window_tree_host;
     // Only used by NativeWidgetAura. Specifies the type of layer for the
-    // aura::Window. Default is WINDOW_LAYER_TEXTURED.
-    aura::WindowLayerType layer_type;
+    // aura::Window. Default is ui::LAYER_TEXTURED.
+    ui::LayerType layer_type;
     // Only used by Aura. Provides a context window whose RootWindow is
     // consulted during widget creation to determine where in the Window
     // hierarchy this widget should be placed. (This is separate from |parent|;