UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36
Platform: 9460.60.0 (Official Build) stable-channel panther

Steps to reproduce the problem:
1. Plug in Arduino Leonardo board to Chromebook/Chromebox USB port
2. Open shell
3. Run "ls /dev/tty*"

What is the expected behavior?
A "/dev/ttACM0" device is listed

What went wrong?
No, "/dev/ttyACM0" device is listed. dmesg reports:

[ 2989.362232] usb 1-1: usbfs: interface 0 claimed by cdc_acm while 'brltty' sets config #1

Did this work before? Yes 57

Chrome version: 59.0.3071.91  Channel: stable
OS Version: 9460.60.0
Flash Version: 

I've tracked down the problem to the introduction of the following brltty patch: https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/master/app-accessibility/brltty/files/brltty-5.4-canute.patch

The "Bristol Canute" is incorrectly using the same USB vendor and product id's as a Arduino Leonardo board. This is preventing Arduino Leonardo users from using their board with Chrome OS as a serial device. I think it would be best to remove the patch linked above for the Bristol Canute as the device is illegally another vendor's USB id.