Fix horizontal scroll direction for xiwi

[ibrado]

xiwi apps scroll horizontally in the opposite direction as ChromeOS. This just reverses the direction via xmodmap and makes scrolling consistent across xiwi and ChromeOS.

Tested with Australian/traditional settings, KDE/XFCE desktops, and separate xiwi windows.

See also #3519

[dnschneid]

If we're applying it unconditionally for xiwi, it would be better just to generate the correct events in the first place: https://github.com/dnschneid/crouton/blob/master/host-ext/nacl_src/kiwi.cc#L624 (and 628).

@drinkcat any reason we're generating the events the way we are? Did something on the Chrome side change in the last 3 years?

[therealbstern]

FYI, this is still a thing on my falco Chromebook without Australian scrolling (two-finger swipe up pans up in a page so things come into view from above).

[joshuafvr]

I tried installing kali Linux on my Samsung s9 thru termux it brings this