WidgetDelegateView is its own contents view.

ash/wm/system_modal_container_layout_manager_unittest.cc

Index: ash/wm/system_modal_container_layout_manager_unittest.cc
diff --git a/ash/wm/system_modal_container_layout_manager_unittest.cc b/ash/wm/system_modal_container_layout_manager_unittest.cc
index dc95fbdea4abf8c834b0b448bec58f1487410ba6..e9e264cfa0d95381cd6967f3991e18f01dd7419a 100644
--- a/ash/wm/system_modal_container_layout_manager_unittest.cc
+++ b/ash/wm/system_modal_container_layout_manager_unittest.cc
@@ -84,7 +84,6 @@ class TestWindow : public views::WidgetDelegateView {
   gfx::Size GetPreferredSize() const override { return gfx::Size(50, 50); }
 
   // Overridden from views::WidgetDelegate:
-  views::View* GetContentsView() override { return this; }
   ui::ModalType GetModalType() const override {
     return modal_ ? ui::MODAL_TYPE_SYSTEM : ui::MODAL_TYPE_NONE;
   }