Description: Explicitly declare that xkb_keymap_key_get_mods_for_level isn't available in focal,
  because compilation fails otherwise (even though it shouldn't because of the weak declaration):
  error: use of undeclared identifier 'xkb_keymap_key_get_mods_for_level'; did you mean 'xkb_keymap_key_get_syms_by_level'?
Author: Olivier Tilloy <olivier.tilloy@canonical.com>

--- a/ui/events/ozone/layout/xkb/xkb_keyboard_layout_engine.cc
+++ b/ui/events/ozone/layout/xkb/xkb_keyboard_layout_engine.cc
@@ -34,10 +34,7 @@
 // xkb_keymap_key_get_mods_for_level is relatively new (introduced in ver 1.0,
 // Sep 6, 2020), thus it is not available on some platform, such as Ubuntu
 // 18.04, which we still supports.
-// Thus declare the function as weak here, so we can check the availability on
-// runtime.
-extern "C" __attribute__((weak)) decltype(
-    xkb_keymap_key_get_mods_for_level) xkb_keymap_key_get_mods_for_level;
+size_t (*xkb_keymap_key_get_mods_for_level)(struct xkb_keymap*, xkb_keycode_t, xkb_layout_index_t, xkb_level_index_t, xkb_mod_mask_t*, size_t) = nullptr;
 
 namespace ui {
 
--- a/ui/events/ozone/layout/xkb/xkb_keyboard_layout_engine_unittest.cc
+++ b/ui/events/ozone/layout/xkb/xkb_keyboard_layout_engine_unittest.cc
@@ -18,8 +18,7 @@
 #include "ui/events/keycodes/keyboard_code_conversion.h"
 #include "ui/events/ozone/layout/scoped_keyboard_layout_engine.h"
 
-extern "C" __attribute__((weak)) decltype(
-    xkb_keymap_key_get_mods_for_level) xkb_keymap_key_get_mods_for_level;
+void* xkb_keymap_key_get_mods_for_level = nullptr;
 
 namespace ui {