DesktopAura: Track windows "owned" via the DesktopWindowTreeHost

ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc

Index: ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
index 5eb0d546515ee37a17bba5c867d3f36b7aa4465a..2361c9ce23ac3c0eb72ad2a48092b8f3e3df41de 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
@@ -37,6 +37,7 @@
 #include "ui/views/window/native_frame_view.h"
 #include "ui/wm/core/compound_event_filter.h"
 #include "ui/wm/core/window_animations.h"
+#include "ui/wm/core/window_util.h"
 #include "ui/wm/public/scoped_tooltip_disabler.h"
 
 DECLARE_WINDOW_PROPERTY_TYPE(views::DesktopWindowTreeHostWin*);
@@ -119,8 +120,10 @@ void DesktopWindowTreeHostWin::Init(aura::Window* content_window,
                         native_widget_delegate_);
 
   HWND parent_hwnd = NULL;
-  if (params.parent && params.parent->GetHost())
+  if (params.parent && params.parent->GetHost()) {
     parent_hwnd = params.parent->GetHost()->GetAcceleratedWidget();
+    wm::AddTransientChild(params.parent, content_window_);
+  }
 
   remove_standard_frame_ = params.remove_standard_frame;
   has_non_client_view_ = Widget::RequiresNonClientView(params.type);