DesktopAura: Track windows "owned" via the DesktopWindowTreeHost

ui/views/widget/desktop_aura/desktop_native_widget_aura.cc

Index: ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
diff --git a/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc b/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
index f442ef1c3cc4400cfc8a4426e465a23510825580..86313b4541669177fb865fa3f5e39dbcc6c59433 100644
--- a/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
+++ b/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
@@ -962,6 +962,18 @@ std::string DesktopNativeWidgetAura::GetName() const {
   return name_;
 }
 
+Widget::Widgets DesktopNativeWidgetAura::GetAllOwnedTopLevelWidgets() const {
+  Widget::Widgets owned;
+  for (DesktopWindowTreeHost* owned_host :
+       desktop_window_tree_host_->GetOwnedTopLevelHosts()) {
+    DesktopNativeWidgetAura* child =
+        ForWindow(owned_host->AsWindowTreeHost()->window());
+    DCHECK(child);
+    owned.insert(child->GetWidget());
+  }
+  return owned;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // DesktopNativeWidgetAura, aura::WindowDelegate implementation: