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

ui/events/event_utils.h

Index: ui/events/event_utils.h
diff --git a/ui/events/event_utils.h b/ui/events/event_utils.h
index 1649bd7eed5364c931f590f472896035eedf6391..2a0e699c28f8ccb02a16a6d213e68cc3274f745f 100644
--- a/ui/events/event_utils.h
+++ b/ui/events/event_utils.h
@@ -116,6 +116,11 @@
 // Gets the touch id from a native event.
 EVENTS_EXPORT int GetTouchId(const base::NativeEvent& native_event);
 
+// Increases the number of times |ClearTouchIdIfReleased| needs to be called on
+// an event with a given touch id before it will actually be cleared.
+EVENTS_EXPORT void IncrementTouchIdRefCount(
+    const base::NativeEvent& native_event);
+
 // Clear the touch id from bookkeeping if it is a release/cancel event.
 EVENTS_EXPORT void ClearTouchIdIfReleased(
     const base::NativeEvent& native_event);