Don't refcount tracking id -> slot id mapping.

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 6678f01dac7983e7a637ae2c6a339409afb16081..6c83976b32e4b3409b5dbf75fb90c0bf9acd97d0 100644
--- a/ui/events/x/events_x.cc
+++ b/ui/events/x/events_x.cc
@@ -739,18 +739,6 @@ void ReleaseCopiedNativeEvent(const base::NativeEvent& event) {
   delete event;
 }
 
-void IncrementTouchIdRefCount(const base::NativeEvent& xev) {
-  ui::DeviceDataManagerX11* manager = ui::DeviceDataManagerX11::GetInstance();
-  double tracking_id;
-  if (!manager->GetEventData(
-          *xev, ui::DeviceDataManagerX11::DT_TOUCH_TRACKING_ID, &tracking_id)) {
-    return;
-  }
-
-  ui::TouchFactory* factory = ui::TouchFactory::GetInstance();
-  factory->AcquireSlotForTrackingID(tracking_id);
-}
-
 void ClearTouchIdIfReleased(const base::NativeEvent& xev) {
   ui::EventType type = ui::EventTypeFromNative(xev);
   if (type == ui::ET_TOUCH_CANCELLED ||