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

ui/events/devices/x11/touch_factory_x11.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_EVENTS_DEVICES_X11_TOUCH_FACTORY_X11_H_
 #define UI_EVENTS_DEVICES_X11_TOUCH_FACTORY_X11_H_
 
 #include <bitset>
 #include <map>
 #include <set>
@@ skipping 116 matching lines @@
   std::map<int, bool> touch_device_list_;
 
   // Touch screen <vid, pid>s.
   std::set<std::pair<int, int> > touchscreen_ids_;
 
   // Device ID of the virtual core keyboard.
   int virtual_core_keyboard_device_;
 
   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);
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_DEVICES_X11_TOUCH_FACTORY_X11_H_