DesktopAura: Track windows "owned" via the DesktopWindowTreeHost

ui/views/widget/native_widget_private.h

Index: ui/views/widget/native_widget_private.h
diff --git a/ui/views/widget/native_widget_private.h b/ui/views/widget/native_widget_private.h
index dfe37828b68d3bcca40d4639ed28eeaa06eff733..83b0b869c53f19e322e7287a4dac3221d17009f0 100644
--- a/ui/views/widget/native_widget_private.h
+++ b/ui/views/widget/native_widget_private.h
@@ -64,7 +64,8 @@ class VIEWS_EXPORT NativeWidgetPrivate : public NativeWidget {
   static void GetAllChildWidgets(gfx::NativeView native_view,
                                  Widget::Widgets* children);
   static void GetAllOwnedWidgets(gfx::NativeView native_view,
-                                 Widget::Widgets* owned);
+                                 Widget::Widgets* owned,
+                                 bool include_toplevel);
   static void ReparentNativeView(gfx::NativeView native_view,
                                  gfx::NativeView new_parent);
 
@@ -233,6 +234,11 @@ class VIEWS_EXPORT NativeWidgetPrivate : public NativeWidget {
 
   // Overridden from NativeWidget:
   internal::NativeWidgetPrivate* AsNativeWidgetPrivate() override;
+
+ private:
+  // Returns the set of top-level Widgets directly owned by |this|. Called
+  // recursively by GetAllOwnedWidgets() to find Widgets indirectly owned.
+  virtual Widget::Widgets GetAllOwnedTopLevelWidgets() const = 0;
 };
 
 }  // namespace internal