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

chrome/service/service_child_process_host.cc

-// 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.
-
-#include "chrome/service/service_child_process_host.h"
-
-#include "base/command_line.h"
-#include "base/logging.h"
-#include "base/process_util.h"
-#include "chrome/common/chrome_switches.h"
-#include "content/public/common/result_codes.h"
-
-#if defined(OS_WIN)
-#include "base/file_path.h"
-#include "content/common/sandbox_policy.h"
-#endif  // defined(OS_WIN)
-
-ServiceChildProcessHost::ServiceChildProcessHost()
-    : handle_(base::kNullProcessHandle) {
-}
-
-ServiceChildProcessHost::~ServiceChildProcessHost() {
-  // We need to kill the child process when the host dies.
-  base::KillProcess(handle_, content::RESULT_CODE_NORMAL_EXIT, false);
-}
-
-bool ServiceChildProcessHost::Launch(CommandLine* cmd_line,
-                                     bool no_sandbox,
-                                     const FilePath& exposed_dir) {
-#if !defined(OS_WIN)
-  // TODO(sanjeevr): Implement for non-Windows OSes.
-  NOTIMPLEMENTED();
-  return false;
-#else  // !defined(OS_WIN)
-
-  if (no_sandbox) {
-    base::ProcessHandle process = base::kNullProcessHandle;
-    cmd_line->AppendSwitch(switches::kNoSandbox);
-    base::LaunchProcess(*cmd_line, base::LaunchOptions(), &handle_);
-  } else {
-    handle_ = sandbox::StartProcessWithAccess(cmd_line, exposed_dir);
-  }
-  return (handle_ != base::kNullProcessHandle);
-#endif  // !defined(OS_WIN)
-}