Remove unused src/butil/memory/ref_counted_delete_on_message_loop.h

src/butil/memory/ref_counted_delete_on_message_loop.h

-// Copyright 2013 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.
-
-#ifndef BUTIL_MEMORY_REF_COUNTED_DELETE_ON_MESSAGE_LOOP_H_
-#define BUTIL_MEMORY_REF_COUNTED_DELETE_ON_MESSAGE_LOOP_H_
-
-#include "butil/location.h"
-#include "butil/logging.h"
-#include "butil/memory/ref_counted.h"
-#include "butil/message_loop/message_loop_proxy.h"
-
-namespace butil {
-
-// RefCountedDeleteOnMessageLoop is similar to RefCountedThreadSafe, and ensures
-// that the object will be deleted on a specified message loop.
-//
-// Sample usage:
-// class Foo : public RefCountedDeleteOnMessageLoop<Foo> {
-//
-//   Foo(const scoped_refptr<MessageLoopProxy>& loop)
-//       : RefCountedDeleteOnMessageLoop<Foo>(loop) {
-//     ...
-//   }
-//   ...
-//  private:
-//   friend class RefCountedDeleteOnMessageLoop<Foo>;
-//   friend class DeleteHelper<Foo>;
-//
-//   ~Foo();
-// };
-
-template <class T>
-class RefCountedDeleteOnMessageLoop : public subtle::RefCountedThreadSafeBase {
- public:
-  RefCountedDeleteOnMessageLoop(
-      const scoped_refptr<MessageLoopProxy>& proxy) : proxy_(proxy) {
-    DCHECK(proxy_.get());
-  }
-
-  void AddRef() const {
-    subtle::RefCountedThreadSafeBase::AddRef();
-  }
-
-  void Release() const {
-    if (subtle::RefCountedThreadSafeBase::Release())
-      DestructOnMessageLoop();
-  }
-
- protected:
-  friend class DeleteHelper<RefCountedDeleteOnMessageLoop>;
-  ~RefCountedDeleteOnMessageLoop() {}
-
-  void DestructOnMessageLoop() const {
-    const T* t = static_cast<const T*>(this);
-    if (proxy_->BelongsToCurrentThread())
-      delete t;
-    else
-      proxy_->DeleteSoon(FROM_HERE, t);
-  }
-
-  scoped_refptr<MessageLoopProxy> proxy_;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(RefCountedDeleteOnMessageLoop);
-};
-
-}  // namespace butil
-
-#endif  // BUTIL_MEMORY_REF_COUNTED_DELETE_ON_MESSAGE_LOOP_H_