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

content/browser/utility_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 "content/browser/utility_process_host.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
+#include "content/common/child_process_host.h"
 #include "content/common/utility_messages.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/common/content_switches.h"
 #include "ipc/ipc_switches.h"
 #include "ui/base/ui_base_switches.h"
 #include "webkit/plugins/plugin_switches.h"
 
 using content::BrowserThread;
 
 UtilityProcessHost::Client::Client() {
@@ skipping 11 matching lines @@
 }
 
 UtilityProcessHost::UtilityProcessHost(Client* client,
                                        BrowserThread::ID client_thread_id)
     : BrowserChildProcessHost(content::PROCESS_TYPE_UTILITY),
       client_(client),
       client_thread_id_(client_thread_id),
       is_batch_mode_(false),
       no_sandbox_(false),
 #if defined(OS_LINUX)
-      child_flags_(CHILD_ALLOW_SELF),
+      child_flags_(ChildProcessHost::CHILD_ALLOW_SELF),
 #else
-      child_flags_(CHILD_NORMAL),
+      child_flags_(ChildProcessHost::CHILD_NORMAL),
 #endif
       started_(false) {
 }
 
 UtilityProcessHost::~UtilityProcessHost() {
   DCHECK(!is_batch_mode_);
 }
 
 bool UtilityProcessHost::Send(IPC::Message* message) {
   if (!StartProcess())
     return false;
 
   return BrowserChildProcessHost::Send(message);
 }
 
 bool UtilityProcessHost::StartBatchMode()  {
   CHECK(!is_batch_mode_);
   is_batch_mode_ = StartProcess();
   Send(new UtilityMsg_BatchMode_Started());
   return is_batch_mode_;
 }
 
 void UtilityProcessHost::EndBatchMode()  {
   CHECK(is_batch_mode_);
   is_batch_mode_ = false;
   Send(new UtilityMsg_BatchMode_Finished());
 }
 
 FilePath UtilityProcessHost::GetUtilityProcessCmd() {
-  return GetChildPath(child_flags_);
+  return ChildProcessHost::GetChildPath(child_flags_);
 }
 
 bool UtilityProcessHost::StartProcess() {
   if (started_)
     return true;
   started_ = true;
 
   if (is_batch_mode_)
     return true;
   // Name must be set or metrics_service will crash in any test which
   // launches a UtilityProcessHost.
   set_name(ASCIIToUTF16("utility process"));
 
-  if (!CreateChannel())
+  if (!child_process_host()->CreateChannel())
     return false;
 
   FilePath exe_path = GetUtilityProcessCmd();
   if (exe_path.empty()) {
     NOTREACHED() << "Unable to get utility process binary name.";
     return false;
   }
 
   CommandLine* cmd_line = new CommandLine(exe_path);
   cmd_line->AppendSwitchASCII(switches::kProcessType,
                               switches::kUtilityProcess);
-  cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id());
+  cmd_line->AppendSwitchASCII(switches::kProcessChannelID,
+                              child_process_host()->channel_id());
   std::string locale =
       content::GetContentClient()->browser()->GetApplicationLocale();
   cmd_line->AppendSwitchASCII(switches::kLang, locale);
 
   const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
   if (browser_command_line.HasSwitch(switches::kChromeFrame))
     cmd_line->AppendSwitch(switches::kChromeFrame);
   if (no_sandbox_ || browser_command_line.HasSwitch(switches::kNoSandbox))
     cmd_line->AppendSwitch(switches::kNoSandbox);
   if (browser_command_line.HasSwitch(switches::kDebugPluginLoading))
@@ skipping 32 matching lines @@
       base::IgnoreReturn<bool>(
           base::Bind(&Client::OnMessageReceived, client_.get(), message)));
   return true;
 }
 
 void UtilityProcessHost::OnProcessCrashed(int exit_code) {
   BrowserThread::PostTask(
       client_thread_id_, FROM_HERE,
       base::Bind(&Client::OnProcessCrashed, client_.get(), exit_code));
 }
-
-bool UtilityProcessHost::CanShutdown() {
-  return true;
-}