RefCounted types should not have public destructors, delegate cleanup

ipc/ipc_message.h

 // Copyright (c) 2012 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 IPC_IPC_MESSAGE_H_
 #define IPC_IPC_MESSAGE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 24 matching lines @@
 
 class Channel;
 class Message;
 struct LogData;
 
 class IPC_EXPORT Message : public Pickle {
  public:
   // Implemented by objects that can send IPC messages across a channel.
   class IPC_EXPORT Sender {
    public:
-    virtual ~Sender() {}
-
     // Sends the given IPC message.  The implementor takes ownership of the
     // given Message regardless of whether or not this method succeeds.  This
     // is done to make this method easier to use.  Returns true on success and
     // false otherwise.
     virtual bool Send(Message* msg) = 0;
+
+   protected:
+    virtual ~Sender() {}
   };
 
   enum PriorityValue {
     PRIORITY_LOW = 1,
     PRIORITY_NORMAL,
     PRIORITY_HIGH
   };
 
   // Bit values used in the flags field.
   enum {
@@ skipping 220 matching lines @@
   MSG_ROUTING_NONE = -2,
 
   // indicates a general message not sent to a particular tab.
   MSG_ROUTING_CONTROL = kint32max,
 };
 
 #define IPC_REPLY_ID 0xFFFFFFF0  // Special message id for replies
 #define IPC_LOGGING_ID 0xFFFFFFF1  // Special message id for logging
 
 #endif  // IPC_IPC_MESSAGE_H_