Remove the use of KeyEvent.keyIdentifier.

ui/file_manager/file_manager/foreground/js/ui/list_container.js

Index: ui/file_manager/file_manager/foreground/js/ui/list_container.js
diff --git a/ui/file_manager/file_manager/foreground/js/ui/list_container.js b/ui/file_manager/file_manager/foreground/js/ui/list_container.js
index 9d7fb65c4d0d4ad0d5b857b0ae98f64c1170eaaa..fed73f516d0eaf0c8d90e290427b1089bb2dcaac 100644
--- a/ui/file_manager/file_manager/foreground/js/ui/list_container.js
+++ b/ui/file_manager/file_manager/foreground/js/ui/list_container.js
@@ -293,13 +293,13 @@ ListContainer.prototype.onKeyDown_ = function(event) {
     return;
   }
 
-  switch (event.keyIdentifier) {
+  switch (event.key) {
     case 'Home':
     case 'End':
-    case 'Up':
-    case 'Down':
-    case 'Left':
-    case 'Right':
+    case 'ArrowUp':
+    case 'ArrowDown':
+    case 'ArrowLeft':
+    case 'ArrowRight':
       // When navigating with keyboard we hide the distracting mouse hover
       // highlighting until the user moves the mouse again.
       this.clearHover();