onPreKeyEvent in keyboardHandler is never called

[baltov]

onPreKey event is never called when some key is pressed.

To Reproduce
Steps to reproduce the behavior:

1. define keyboardhandler, attach it to client
2. log a message when onPreKeyEvent is called
3. log is not printed

client_ = cefApp_.createClient();
client_.addKeyboardHandler(keyboardHandler);
..........
@OverRide
public boolean onPreKeyEvent(CefBrowser browser, CefKeyEvent event, BoolRef is_keyboard_shortcut) {
log.info("OnPreKeyEvent: {}", event); /// Never called
return false
}

Expected behavior
onPreKeyEvent event to be used