DesktopAura: Track windows "owned" via the DesktopWindowTreeHost

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc

Index: ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
index 3b848bc9ddb9aa899dc8eaf96f30a0a97998e5b1..ea20c3a34bdb83adeec170717ae4f985e26d0db8 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
@@ -1182,6 +1182,12 @@ bool DesktopWindowTreeHostX11::ShouldUseDesktopNativeCursorManager() const {
   return true;
 }
 
+std::vector<DesktopWindowTreeHost*>
+DesktopWindowTreeHostX11::GetOwnedTopLevelHosts() const {
+  return std::vector<DesktopWindowTreeHost*>(window_children_.begin(),
+                                             window_children_.end());
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // DesktopWindowTreeHostX11, aura::WindowTreeHost implementation: