x11: Make sure each XI2 key-event is not processed twice.

ui/events/x/touch_factory_x11.cc

 // 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.
 
 #include "ui/events/x/touch_factory_x11.h"
 
 #include <X11/Xatom.h>
 #include <X11/cursorfont.h>
 #include <X11/extensions/XInput.h>
 #include <X11/extensions/XInput2.h>
@@ skipping 156 matching lines @@
   XIEvent* event = static_cast<XIEvent*>(xev->xcookie.data);
   XIDeviceEvent* xiev = reinterpret_cast<XIDeviceEvent*>(event);
 
 #if defined(USE_XI2_MT)
   if (event->evtype == XI_TouchBegin ||
       event->evtype == XI_TouchUpdate ||
       event->evtype == XI_TouchEnd) {
     return !touch_events_disabled_ && IsTouchDevice(xiev->deviceid);
   }
 #endif
+  // Make sure only key-events from the master device are processed.
+  if (event->evtype == XI_KeyPress || event->evtype == XI_KeyRelease)
+    return xiev->deviceid == xiev->sourceid;
+
   if (event->evtype != XI_ButtonPress &&
       event->evtype != XI_ButtonRelease &&
       event->evtype != XI_Motion)
     return true;
 
   if (!pointer_device_lookup_[xiev->deviceid])
     return false;
 
   return IsTouchDevice(xiev->deviceid) ? !touch_events_disabled_ : true;
 }
@@ skipping 131 matching lines @@
       if (ptr[0] || ptr[1])
         touchscreen_ids_.insert(std::make_pair(ptr[0], ptr[1]));
     }
     XFree(prop_return);
   }
 
   XCloseDevice(display, device);
 }
 
 }  // namespace ui