window: Remove suspicious branch

It seems this branch is not needed anymore. It was originally added in
1999 to support gtk_widget_realize(), but all those reasons seem
obsolete today.
Instead just call gtk_widget_realize().

If you end up at this commit when bisecting:
There is no bug that made me remove this code, it was purely meant to be
cleanup / dead code removal. I seem to have introduced a new bug or
bisecting wouldn't have let you here. So it seems we should just revert
this commit.

gtk/gtkwindow.c

@@ -6087,7 +6087,6 @@ gtk_window_show (GtkWidget *widget)
   GtkWindow *window = GTK_WINDOW (widget);
   GtkWindowPrivate *priv = window->priv;
   GtkContainer *container = GTK_CONTAINER (window);
-  gboolean need_resize;
   gboolean is_plug;
 
   if (!_gtk_widget_is_toplevel (GTK_WIDGET (widget)))
@@ -6098,62 +6097,10 @@ gtk_window_show (GtkWidget *widget)
 
   _gtk_widget_set_visible_flag (widget, TRUE);
 
-  need_resize = _gtk_widget_get_alloc_needed (widget) || !_gtk_widget_get_realized (widget);
-
   gtk_css_node_validate (gtk_widget_get_css_node (widget));
 
-  if (need_resize)
+  gtk_widget_realize (widget);
-    {
-      GtkWindowGeometryInfo *info = gtk_window_get_geometry_info (window, TRUE);
-      GtkAllocation allocation = { 0, 0 };
-      GdkRectangle configure_request;
-      GdkGeometry new_geometry;
-      guint new_flags;
-      gboolean was_realized;
 
-      /* We are going to go ahead and perform this configure request
-       * and then emulate a configure notify by going ahead and
-       * doing a size allocate. Sort of a synchronous
-       * mini-copy of gtk_window_move_resize() here.
-       */
-      gtk_window_compute_configure_request (window,
-                                            &configure_request,
-                                            &new_geometry,
-                                            &new_flags);
-      
-      /* We update this because we are going to go ahead
-       * and gdk_window_resize() below, rather than
-       * queuing it.
-       */
-      info->last.configure_request = configure_request;
-      
-      /* and allocate the window - this is normally done
-       * in move_resize in response to configure notify
-       */
-      allocation.width  = configure_request.width;
-      allocation.height = configure_request.height;
-      gtk_widget_size_allocate (widget, &allocation);
-
-      /* Then we guarantee we have a realize */
-      was_realized = FALSE;
-      if (!_gtk_widget_get_realized (widget))
-	{
-	  gtk_widget_realize (widget);
-	  was_realized = TRUE;
-	}
-
-      /* We only send configure request if we didn't just finish
-       * creating the window; if we just created the window
-       * then we created it with widget->allocation anyhow.
-       */
-      if (!was_realized)
-        gdk_window_move_resize (_gtk_widget_get_window (widget),
-				configure_request.x,
-				configure_request.y,
-				configure_request.width,
-				configure_request.height);
-    }
-  
   gtk_container_check_resize (container);
 
   gtk_widget_map (widget);