Autotest: reduce X dependency for touch_* tests

Find all touchpad, touchscreen, and mice on a device without using xinput
calls.  Do so by cycling through all /dev/input/event*, checking for flags
which identify their types.

BUG=chromium:413143
TEST=this; ran all tests which use this base file

Change-Id: Id45439477a7a3d6928144878a1c3d84f1ca3f547
Reviewed-on: https://chromium-review.googlesource.com/226832
Reviewed-by: Katherine Threlkeld <kathrelkeld@chromium.org>
Commit-Queue: Katherine Threlkeld <kathrelkeld@chromium.org>
Tested-by: Katherine Threlkeld <kathrelkeld@chromium.org>
1 file changed