Fix: RefCountInterface: Make AddRef() and Release() const

webrtc/base/refcount.h

 /*
  *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 77 matching lines @@
 
   template<typename P1, typename P2, typename P3, typename P4, typename P5,
            typename P6, typename P7, typename P8, typename P9, typename P10,
            typename P11>
   RefCountedObject(
       P1 p1, P2 p2, P3 p3, P4 p4, P5 p5, P6 p6, P7 p7, P8 p8, P9 p9, P10 p10,
       P11 p11)
   : T(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11), ref_count_(0) {
   }
 
-  int AddRef() const override {
+  virtual int AddRef() const {
     return AtomicOps::Increment(&ref_count_);
   }
 
-  int Release() const override {
+  virtual int Release() const {
     int count = AtomicOps::Decrement(&ref_count_);
     if (!count) {
       delete this;
     }
     return count;
   }
 
   // Return whether the reference count is one. If the reference count is used
   // in the conventional way, a reference count of 1 implies that the current
   // thread owns the reference and no other thread shares it. This call
   // performs the test for a reference count of one, and performs the memory
   // barrier needed for the owning thread to act on the object, knowing that it
   // has exclusive access to the object.
   virtual bool HasOneRef() const {
     return AtomicOps::AcquireLoad(&ref_count_) == 1;
   }
 
  protected:
   virtual ~RefCountedObject() {
   }
 
   mutable volatile int ref_count_;
 };
 
 }  // namespace rtc
 
 #endif  // WEBRTC_BASE_REFCOUNT_H_