Merge 285580 "Currently, destroying a ui::TouchEvent removes its..."

ui/events/x/touch_factory_x11.cc

Index: ui/events/x/touch_factory_x11.cc
===================================================================
--- ui/events/x/touch_factory_x11.cc	(revision 286562)
+++ ui/events/x/touch_factory_x11.cc	(working copy)
@@ -250,8 +250,14 @@
   return id_generator_.GetGeneratedID(tracking_id);
 }
 
+void TouchFactory::AcquireSlotForTrackingID(uint32 tracking_id) {
+  tracking_id_refcounts_[tracking_id]++;
+}
+
 void TouchFactory::ReleaseSlotForTrackingID(uint32 tracking_id) {
-  id_generator_.ReleaseNumber(tracking_id);
+  tracking_id_refcounts_[tracking_id]--;
+  if (tracking_id_refcounts_[tracking_id] == 0)
+    id_generator_.ReleaseNumber(tracking_id);
 }
 
 bool TouchFactory::IsTouchDevicePresent() {