Revert of Support XI2 in PlatformKeycodeFromNative()

ui/events/x/events_x.cc

Index: ui/events/x/events_x.cc
diff --git a/ui/events/x/events_x.cc b/ui/events/x/events_x.cc
index c9aecd1900347d2a22ff7bc78986746324b6ed74..03b7e28d8de9704453e90d7dde5a6e126667863b 100644
--- a/ui/events/x/events_x.cc
+++ b/ui/events/x/events_x.cc
@@ -579,36 +579,8 @@
 }
 
 uint32 PlatformKeycodeFromNative(const base::NativeEvent& native_event) {
-  XKeyEvent* xkey = NULL;
-  XEvent xkey_from_xi2;
-  switch (native_event->type) {
-    case KeyPress:
-    case KeyRelease:
-      xkey = &native_event->xkey;
-      break;
-    case GenericEvent: {
-      XIDeviceEvent* xievent =
-          static_cast<XIDeviceEvent*>(native_event->xcookie.data);
-      switch (xievent->evtype) {
-        case XI_KeyPress:
-        case XI_KeyRelease:
-          // Build an XKeyEvent corresponding to the XI2 event,
-          // so that we can call XLookupString on it.
-          InitXKeyEventFromXIDeviceEvent(*native_event, &xkey_from_xi2);
-          xkey = &xkey_from_xi2.xkey;
-          break;
-        default:
-          NOTREACHED();
-          break;
-      }
-    }
-    default:
-      NOTREACHED();
-      break;
-  }
-  KeySym keysym = XK_VoidSymbol;
-  if (xkey)
-    XLookupString(xkey, NULL, 0, &keysym, NULL);
+  KeySym keysym;
+  XLookupString(&native_event->xkey, NULL, 0, &keysym, NULL);
   return keysym;
 }