Convert mojo::system::ChannelEndpointClient to use our new refcounting stuff (instead of base's).

mojo/edk/system/ref_counted.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Provides a base class for reference-counted classes.
 
 #ifndef MOJO_EDK_SYSTEM_REF_COUNTED_H_
 #define MOJO_EDK_SYSTEM_REF_COUNTED_H_
 
 #include <assert.h>
@@ skipping 57 matching lines @@
  public:
   void Release() const {
     if (internal::RefCountedThreadSafeBase::Release())
       delete static_cast<const T*>(this);
   }
 
  protected:
   RefCountedThreadSafe() {}
   ~RefCountedThreadSafe() {}
 
+ private:
 #ifndef NDEBUG
   template <typename U>
   friend RefPtr<U> AdoptRef(U*);
   void Adopt() { internal::RefCountedThreadSafeBase::Adopt(); }
 #endif
 
- private:
   MOJO_DISALLOW_COPY_AND_ASSIGN(RefCountedThreadSafe);
 };
 
 // If you subclass |RefCountedThreadSafe| and want to keep your destructor
 // private, use this. (See the example above |RefCountedThreadSafe|.)
 #define FRIEND_REF_COUNTED_THREAD_SAFE(T) \
   friend class ::mojo::system::RefCountedThreadSafe<T>
 
 // If you want to keep your constructor(s) private and still want to use
 // |MakeRefCounted<T>()|, use this. (See the example above
 // |RefCountedThreadSafe|.)
 #define FRIEND_MAKE_REF_COUNTED(T) \
   friend class ::mojo::system::internal::MakeRefCountedHelper<T>
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_REF_COUNTED_H_