LibCore: Make CObject reference-counted

Okay, I've spent a whole day on this now, and it finally kinda works!
With this patch, CObject and all of its derived classes are reference
counted instead of tree-owned.

The previous, Qt-like model was nice and familiar, but ultimately also
outdated and difficult to reason about.

CObject-derived types should now be stored in RefPtr/NonnullRefPtr and
each class can be constructed using the forwarding construct() helper:

    auto widget = GWidget::construct(parent_widget);

Note that construct() simply forwards all arguments to an existing
constructor. It is inserted into each class by the C_OBJECT macro,
see CObject.h to understand how that works.

CObject::delete_later() disappears in this patch, as there is no longer
a single logical owner of a CObject.

1 files changed, 1 insertions, 1 deletions

diff --git a/Servers/WindowServer/WSWindow.h b/Servers/WindowServer/WSWindow.h
index c014c9df81..9ed46b07d4 100644
--- a/Servers/WindowServer/WSWindow.h
+++ b/Servers/WindowServer/WSWindow.h
@@ -182,5 +182,5 @@ private:
     unsigned m_wm_event_mask { 0 };
     DisjointRectSet m_pending_paint_rects;
     Rect m_unmaximized_rect;
-    OwnPtr<WSMenu> m_window_menu;
+    RefPtr<WSMenu> m_window_menu;
 };