RefCounted types should not have public destructors, delegate cleanup

ppapi/proxy/host_dispatcher.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 PPAPI_PROXY_HOST_DISPATCHER_H_
 #define PPAPI_PROXY_HOST_DISPATCHER_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 14 matching lines @@
 
 class PPAPI_PROXY_EXPORT HostDispatcher : public Dispatcher {
  public:
   // This interface receives notifications about sync messages being sent by
   // the dispatcher to the plugin process. It is used to detect a hung plugin.
   //
   // Note that there can be nested sync messages, so the begin/end status
   // actually represents a stack of blocking messages.
   class SyncMessageStatusReceiver : public IPC::ChannelProxy::MessageFilter {
    public:
-    virtual ~SyncMessageStatusReceiver() {}
-
     // Notification that a sync message is about to be sent out.
     virtual void BeginBlockOnSyncMessage() = 0;
 
     // Notification that a sync message reply was received and the dispatcher
     // is no longer blocked on a sync message.
     virtual void EndBlockOnSyncMessage() = 0;
+
+   protected:
+    virtual ~SyncMessageStatusReceiver() {}
   };
 
   // Constructor for the renderer side. This will take a reference to the
   // SyncMessageStatusReceiver.
   //
   // You must call InitHostWithChannel after the constructor.
   HostDispatcher(PP_Module module,
                  PP_GetInterface_Func local_get_interface,
                  SyncMessageStatusReceiver* sync_status);
   ~HostDispatcher();
@@ skipping 90 matching lines @@
  private:
   HostDispatcher* dispatcher_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedModuleReference);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_HOST_DISPATCHER_H_