It looks a bit odd that scrollbars stay over treeview headers and
similar, seems nicer to just avoid the border regions.
https://bugzilla.gnome.org/show_bug.cgi?id=751805
priv = scrolled_window->priv;
- gtk_scrolled_window_relative_allocation (widget, &content_allocation);
+ gtk_scrolled_window_inner_allocation (widget, &content_allocation);
sb_spacing = _gtk_scrolled_window_get_scrollbar_spacing (scrolled_window);
gtk_widget_get_preferred_height (priv->hscrollbar, &sb_height, NULL);
gtk_widget_get_preferred_width (priv->vscrollbar, &sb_width, NULL);