My laptop Down arrow key is stuck on, so I have used Xmodmap to remove the mapping of that key with the following command:
The contents of my .Xmodmap file is just the single line:
keycode 116 =
All programs in Ubuntu (such as gnome-terminal, xterm, Firefox, gedit) respect this mapping.
However, Google Chrome ignores this mapping, resulting in the page continually scrolling down or the volume being decreased when a full screen video is playing.
Both of which had no available solution.
The solution from https://github.com/dnschneid/crouton/wiki/Keyboard to disable the keyboard layout management with:
gsettings set org.gnome.settings-daemon.plugins.keyboard active false
is not suitable for me as I need to enter Japanese characters so I need the IME to be available to swap between English and Japanese.