Fix touch screen on Linux with or without flag --touch-devices

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 43174a7dbd00a3d2b09f6390b360a7d224a6a52a..c2e95802deea66f3cf39312efff3e0a744e3c3f8 100644
--- a/ui/events/devices/x11/touch_factory_x11.h
+++ b/ui/events/devices/x11/touch_factory_x11.h
@@ -134,6 +134,9 @@ class EVENTS_DEVICES_EXPORT TouchFactory {
 
   SequentialIDGenerator id_generator_;
 
+  // Associate each device ID with its master device ID.
+  std::map<int, int> device_master_id_list_;
+
   DISALLOW_COPY_AND_ASSIGN(TouchFactory);
 };