Add slave touch device to touch_device_lookup_ and touch_device_list_

ui/events/devices/x11/touch_factory_x11.h

Index: ui/events/devices/x11/touch_factory_x11.h
diff --git a/ui/events/devices/x11/touch_factory_x11.h b/ui/events/devices/x11/touch_factory_x11.h
index b8a37fc8ae0c3db6c841c005b39292b29e78a3e7..1712d55839ef6f13531b6d85a3923b94e51fc818 100644
--- a/ui/events/devices/x11/touch_factory_x11.h
+++ b/ui/events/devices/x11/touch_factory_x11.h
@@ -121,9 +121,6 @@ class EVENTS_DEVICES_X11_EXPORT TouchFactory {
   // should be processed.
   std::bitset<kMaxDeviceNum> pointer_device_lookup_;
 
-  // A quick lookup table for determining if a device is a touch device.
-  std::bitset<kMaxDeviceNum> touch_device_lookup_;
-
   // The list of touch devices. For testing/debugging purposes, a single-pointer
   // device (mouse or touch screen without sufficient X/driver support for MT)
   // can sometimes be treated as a touch device. The key in the map represents