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

chrome/browser/nacl_host/nacl_broker_host_win.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/browser/nacl_host/nacl_broker_host_win.h"
 
 #include "base/command_line.h"
 #include "base/path_service.h"
 #include "ipc/ipc_switches.h"
 #include "chrome/browser/nacl_host/nacl_broker_service_win.h"
 #include "chrome/browser/nacl_host/nacl_process_host.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/logging_chrome.h"
 #include "chrome/common/nacl_cmd_line.h"
 #include "chrome/common/nacl_messages.h"
+#include "content/common/child_process_host.h"
 
 NaClBrokerHost::NaClBrokerHost()
     : BrowserChildProcessHost(content::PROCESS_TYPE_NACL_BROKER),
       stopping_(false) {
 }
 
 NaClBrokerHost::~NaClBrokerHost() {
 }
 
 bool NaClBrokerHost::Init() {
   // Create the channel that will be used for communicating with the broker.
-  if (!CreateChannel())
+  if (!child_process_host()->CreateChannel())
     return false;
 
   // Create the path to the nacl broker/loader executable.
   FilePath module_path;
   if (!PathService::Get(base::FILE_MODULE, &module_path))
     return false;
 
   FilePath nacl_path = module_path.DirName().Append(chrome::kNaClAppName);
   CommandLine* cmd_line = new CommandLine(nacl_path);
   nacl::CopyNaClCommandLineArguments(cmd_line);
 
   cmd_line->AppendSwitchASCII(switches::kProcessType,
                               switches::kNaClBrokerProcess);
-  cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id());
+  cmd_line->AppendSwitchASCII(switches::kProcessChannelID,
+                              child_process_host()->channel_id());
   if (logging::DialogsAreSuppressed())
     cmd_line->AppendSwitch(switches::kNoErrorDialogs);
 
   BrowserChildProcessHost::Launch(FilePath(), cmd_line);
   return true;
 }
 
 bool NaClBrokerHost::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(NaClBrokerHost, msg)
@@ skipping 10 matching lines @@
 
 void NaClBrokerHost::OnLoaderLaunched(const std::wstring& loader_channel_id,
                                       base::ProcessHandle handle) {
   NaClBrokerService::GetInstance()->OnLoaderLaunched(loader_channel_id, handle);
 }
 
 void NaClBrokerHost::StopBroker() {
   stopping_ = true;
   Send(new NaClProcessMsg_StopBroker());
 }