[gtk] inspector: Fix a small memory leak

[Matthias Clasen <matthiasc src gnome org>]

commit 280bdb0567ce51565fc16c587a8ee361ce54a36e
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Dec 24 19:42:14 2019 -0500

    inspector: Fix a small memory leak
    
    We were leaking overlays.

 gtk/inspector/window.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/gtk/inspector/window.c b/gtk/inspector/window.c
index 2d82629124..6b4b2524d5 100644
--- a/gtk/inspector/window.c
+++ b/gtk/inspector/window.c
@@ -284,6 +284,8 @@ gtk_inspector_window_dispose (GObject *object)
 
   g_object_set_data (G_OBJECT (iw->inspected_display), "-gtk-inspector", NULL);
 
+  g_clear_object (&iw->flash_overlay);
+
   G_OBJECT_CLASS (gtk_inspector_window_parent_class)->dispose (object);
 }
 
@@ -539,6 +541,7 @@ gtk_inspector_window_remove_overlay (GtkInspectorWindow  *iw,
   gtk_inspector_overlay_queue_draw (overlay);
 
   iw->overlays = g_list_delete_link (iw->overlays, item);
+  g_object_unref (overlay);
 }
 
 static GtkInspectorWindow *