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

content/browser/plugin_loader_posix.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/plugin_loader_posix.h"
 
 #include "base/bind.h"
 #include "base/message_loop.h"
 #include "base/message_loop_proxy.h"
 #include "base/metrics/histogram.h"
+#include "content/common/child_process_host.h"
 #include "content/common/utility_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "webkit/plugins/npapi/plugin_list.h"
 
 using content::BrowserThread;
 
 PluginLoaderPosix::PluginLoaderPosix()
     : next_load_index_(0) {
 }
 
@@ skipping 147 matching lines @@
 
 PluginLoaderPosix::PendingCallback::PendingCallback(
     scoped_refptr<base::MessageLoopProxy> loop,
     const PluginService::GetPluginsCallback& cb)
     : target_loop(loop),
       callback(cb) {
 }
 
 PluginLoaderPosix::PendingCallback::~PendingCallback() {
 }