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

chrome/service/service_child_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_SERVICE_SERVICE_CHILD_PROCESS_HOST_H_
-#define CHROME_SERVICE_SERVICE_CHILD_PROCESS_HOST_H_
-#pragma once
-
-#include "base/process.h"
-#include "content/common/child_process_host.h"
-
-class CommandLine;
-
-// Plugins/workers and other child processes that live on the IO thread should
-// derive from this class.
-//
-class ServiceChildProcessHost : public ChildProcessHost {
- public:
-  virtual ~ServiceChildProcessHost();
-
- protected:
-  ServiceChildProcessHost();
-
-  // Derived classes call this to launch the child process synchronously.
-  // TODO(sanjeevr): Determine whether we need to make the launch asynchronous.
-  // |exposed_dir| is the path to tbe exposed to the sandbox. This is ignored
-  // if |no_sandbox| is true.
-  bool Launch(CommandLine* cmd_line,
-              bool no_sandbox,
-              const FilePath& exposed_dir);
-
-  base::ProcessHandle handle() const { return handle_; }
-
- private:
-  base::ProcessHandle handle_;
-
-  DISALLOW_COPY_AND_ASSIGN(ServiceChildProcessHost);
-};
-
-#endif  // CHROME_SERVICE_SERVICE_CHILD_PROCESS_HOST_H_