[gtk] filechooser: Remove outdated hack

[Matthias Clasen <matthiasc src gnome org>]

commit 810f55c006aed123b7f4b2cb66ecee3a9d248c70
Author: Benjamin Otte <otte redhat com>
Date:   Sun Aug 26 18:00:52 2018 +0200

    filechooser: Remove outdated hack
    
    In GTK2, the filechooser was using a Paned, so switching between sidebar
    and files list with the arrow keys didn't work (the slider would be
    selected instead). So in
    https://bugzilla.gnome.org/show_bug.cgi?id=161489 a crude hack was added
    to make this possible.
    
    Over the years the filechooser code has changed so that it now would do
    this by default, yet the hack had been retained.

 gtk/gtkfilechooserwidget.c | 21 ---------------------
 1 file changed, 21 deletions(-)
---
diff --git a/gtk/gtkfilechooserwidget.c b/gtk/gtkfilechooserwidget.c
index a1e1e29128..f561e8d293 100644
--- a/gtk/gtkfilechooserwidget.c
+++ b/gtk/gtkfilechooserwidget.c
@@ -1287,21 +1287,6 @@ places_sidebar_show_error_message_cb (GtkPlacesSidebar *sidebar,
   error_message (impl, primary, secondary);
 }
 
-static gboolean
-key_is_left_or_right (guint keyval,
-                      guint state)
-{
-  guint modifiers;
-
-  modifiers = gtk_accelerator_get_default_mod_mask ();
-
-  return ((keyval == GDK_KEY_Right
-           || keyval == GDK_KEY_KP_Right
-           || keyval == GDK_KEY_Left
-           || keyval == GDK_KEY_KP_Left)
-          && (state & modifiers) == 0);
-}
-
 static gboolean
 should_trigger_location_entry (GtkFileChooserWidget *impl,
                                guint                 keyval,
@@ -1363,12 +1348,6 @@ treeview_key_press_cb (GtkEventControllerKey *controller,
       return GDK_EVENT_STOP;
     }
 
-  if (key_is_left_or_right (keyval, state))
-    {
-      if (gtk_widget_child_focus (priv->places_sidebar, GTK_DIR_LEFT))
-        return GDK_EVENT_STOP;
-    }
-
   if ((keyval == GDK_KEY_Return
        || keyval == GDK_KEY_ISO_Enter
        || keyval == GDK_KEY_KP_Enter