The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/chromite/+/02525110cc229f36ea0ca95ffa3c1a00435bf6c3

commit 02525110cc229f36ea0ca95ffa3c1a00435bf6c3
Author: Nicolas Norvez <norvez@chromium.org>
Date: Sat Dec 02 01:57:54 2017

cros_vm: Pass '-usbdevice tablet' to qemu

If we don't use absolute coordinates the mouse pointer in the VM is
offset. Pass '-usbdevice tablet' to qemu to use absolute coordinates.

BUG= chromium:790813 
TEST=Ran betty image in cros_vm, (chroot's qemu), mouse pointer is now
correct

Change-Id: Ieeb4a94c474ab99fbc98625079bd02ef46483407
Reviewed-on: https://chromium-review.googlesource.com/802458
Commit-Ready: Nicolas Norvez <norvez@chromium.org>
Tested-by: Nicolas Norvez <norvez@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>

[modify] https://crrev.com/02525110cc229f36ea0ca95ffa3c1a00435bf6c3/scripts/cros_vm.py