Don't make classes derive from ChildProcessHost, and instead have them use it through composition...

chrome/browser/nacl_host/nacl_process_host.h

 // Copyright (c) 2011 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 CHROME_BROWSER_NACL_HOST_NACL_PROCESS_HOST_H_
 #define CHROME_BROWSER_NACL_HOST_NACL_PROCESS_HOST_H_
 #pragma once
 
 #include "build/build_config.h"
 
@@ skipping 25 matching lines @@
               int socket_count,
               IPC::Message* reply_msg);
 
   virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
 
   void OnProcessLaunchedByBroker(base::ProcessHandle handle);
 
  protected:
   virtual base::TerminationStatus GetChildTerminationStatus(
       int* exit_code) OVERRIDE;
-  virtual void OnChildDied() OVERRIDE;
 
  private:
   // Internal class that holds the nacl::Handle objecs so that
   // nacl_process_host.h doesn't include NaCl headers.  Needed since it's
   // included by src\content, which can't depend on the NaCl gyp file because it
   // depends on chrome.gyp (circular dependency).
   struct NaClInternal;
 
   bool LaunchSelLdr();
 
   virtual void OnProcessLaunched() OVERRIDE;
 
   void IrtReady();
   void SendStart(base::PlatformFile irt_file);
 
-  virtual bool CanShutdown() OVERRIDE;
-
  private:
   // The ChromeRenderMessageFilter that requested this NaCl process.  We use
   // this for sending the reply once the process has started.
   scoped_refptr<ChromeRenderMessageFilter> chrome_render_message_filter_;
 
   // The reply message to send.
   IPC::Message* reply_msg_;
 
   // Socket pairs for the NaCl process and renderer.
   scoped_ptr<NaClInternal> internal_;
 
   base::WeakPtrFactory<NaClProcessHost> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NaClProcessHost);
 };
 
 #endif  // CHROME_BROWSER_NACL_HOST_NACL_PROCESS_HOST_H_