Update from https://crrev.com/309415

base/bind_internal.h.pump

 $$ This is a pump file for generating file templates.  Pump is a python
 $$ script that is part of the Google Test suite of utilities.  Description
 $$ can be found here:
 $$
 $$ http://code.google.com/p/googletest/wiki/PumpManual
 $$
 
 $$ See comment for MAX_ARITY in base/bind.h.pump.
 $var MAX_ARITY = 7
 $range ARITY 0..MAX_ARITY
@@ skipping 474 matching lines @@
 ]] $else [[
 , $for ARG , [[
 
         p$(ARG)_(p$(ARG))
 ]] {
     MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::AddRef(p1_);
 
 ]]
   }
 
-  virtual ~BindState() {
-$if ARITY > 0 [[
-    MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::Release(p1_);
-]]
-  }
-
   RunnableType runnable_;
 
 $for ARG [[
   P$(ARG) p$(ARG)_;
 
 ]]
+
+ private:
+  ~BindState() override {
+$if ARITY > 0 [[
+    MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::Release(p1_);
+]]
+  }
+
 };
 
 ]] $$ for ARITY
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_BIND_INTERNAL_H_