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

Because we listen to XInput2 events on AllDevices, we receive an event from
the slave device, followed by an event from the master device. It is not
necessary to process the events from the slave device, so ignore them.

BUG=368750
R=kpschoedel@chromium.org

Review URL: https://codereview.chromium.org/402763002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283879 0039d316-1c4b-4281-b951-d872f2087c98

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)