Remove unused method (flutter#161572)

Author: robert-ancell

engine/src/flutter/shell/platform/linux/fl_keyboard_manager.cc

@@ -592,11 +592,6 @@ void fl_keyboard_manager_set_lookup_key_handler(
   self->lookup_key_handler_user_data = user_data;
 }
 
-void fl_keyboard_manager_notify_layout_changed(FlKeyboardManager* self) {
-  g_return_if_fail(FL_IS_KEYBOARD_MANAGER(self));
-  keymap_keys_changed_cb(self);
-}
-
 void fl_keyboard_manager_set_redispatch_handler(
     FlKeyboardManager* self,
     FlKeyboardManagerRedispatchEventHandler redispatch_handler,

engine/src/flutter/shell/platform/linux/fl_keyboard_manager.h

@@ -125,15 +125,6 @@ void fl_keyboard_manager_set_lookup_key_handler(
     FlKeyboardManagerLookupKeyHandler lookup_key_handler,
     gpointer user_data);
 
-/**
- * fl_keyboard_manager_notify_layout_changed:
- * @manager: the #FlKeyboardManager self.
- *
- * Notify the manager the keyboard layout has changed, for testing purposes
- * only.
- */
-void fl_keyboard_manager_notify_layout_changed(FlKeyboardManager* manager);
-
 typedef void (*FlKeyboardManagerRedispatchEventHandler)(FlKeyEvent* event,
                                                         gpointer user_data);