am d144748d: Merge "Add missing include"

* commit 'd144748d4767b2ccfb13857e23f78bc944e9531d':
  Add missing include
diff --git a/include/utils/RefBase.h b/include/utils/RefBase.h
index 0af7e6a..d92cfb0 100644
--- a/include/utils/RefBase.h
+++ b/include/utils/RefBase.h
@@ -115,7 +115,6 @@
     // used to override the RefBase destruction.
     class Destroyer {
         friend class RefBase;
-        friend class weakref_type;
     public:
         virtual ~Destroyer();
     private: