Log Message:
Update gtk3 to 3.22.4

Some highlights:

* Deprecations have been added for APIs that will be removed in GTK+ 4
* GtkHeaderBar supports expanding children
* GtkApplication supports registering with the Xfce session manager
* Keep firefox working after the introduction of GdkDrawingContext
* New APIs:
 - gtk_show_uri_on_window
 - gtk_file_filter_to/from_gvariant
 - gtk_file_chooser_add/remove/set/get_choice
 - gtk_print_settings_to/from_gvariant
 - gtk_paper_size_to/from_gvariant
 - gtk_page_setup_to/from_gvariant
* GDK has a new GdkMonitor api that offers richer information about
  connected outputs
* GdkSeat and GdkDevice gained API for device tools, to support drawing tablets
* 773180 Don't second-guess whether our GDK GL context is GLES
* 743746 Add GLES 2.0 (and/or 3.0) profile
* Translation updates

Full list of changes available at:

  https://git.gnome.org/browse/gtk+/tree/NEWS?h=3.22.4