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

ui/events/x/touch_factory_x11.cc

Index: ui/events/x/touch_factory_x11.cc
diff --git a/ui/events/x/touch_factory_x11.cc b/ui/events/x/touch_factory_x11.cc
index 9df436c803002538e61d8ec06b8bc48699d13ed1..e6a2fe2724cad4d1d1c03e03d2e9338c7248444b 100644
--- a/ui/events/x/touch_factory_x11.cc
+++ b/ui/events/x/touch_factory_x11.cc
@@ -174,6 +174,10 @@ bool TouchFactory::ShouldProcessXI2Event(XEvent* xev) {
     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)