GtkWindow: add up CSD size in gtk_window_resize()
GtkWindow: add up CSD size in gtk_window_resize()

When client side decoration is used, the size passed to
gtk_window_resize() or retrieved from gtk_window_get_size() for top-
level windows also accounts for the client side decorations widgets
such as the title bar or the shadow borders.

Add up the size of these additional controls to the given size to get
the size expected.

Bugzilla: https://bugzilla.gnome.org/show_bug.cgi?id=756618

grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,alexlarsson/gtk,alexlarsson/gtk,alexlarsson/gtk,grubersjoe/adwaita,alexlarsson/gtk,grubersjoe/adwaita,alexlarsson/gtk,grubersjoe/adwaita,grubersjoe/adwaita,alexlarsson/gtk,grubersjoe/adwaita,alexlarsson/gtk,alexlarsson/gtk