Add ChildMessageFilter, a base class for renderer/worker cross-thread MessageFilter

content/worker/worker_thread.cc

 // Copyright (c) 2012 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/worker/worker_thread.h"
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/threading/thread_local.h"
 #include "content/child/appcache/appcache_dispatcher.h"
@@ skipping 33 matching lines @@
       new AppCacheDispatcher(this, new AppCacheFrontendImpl()));
 
   web_database_observer_impl_.reset(
       new WebDatabaseObserverImpl(sync_message_filter()));
   blink::WebDatabase::setObserver(web_database_observer_impl_.get());
   db_message_filter_ = new DBMessageFilter();
   channel()->AddFilter(db_message_filter_.get());
 
   indexed_db_message_filter_ = new IndexedDBMessageFilter(
       thread_safe_sender());
-  channel()->AddFilter(indexed_db_message_filter_.get());
+  channel()->AddFilter(indexed_db_message_filter_->GetFilter());
 
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   SetRuntimeFeaturesDefaultsAndUpdateFromArgs(command_line);
 }
 
 void WorkerThread::OnShutdown() {
   // The worker process is to be shut down gracefully. Ask the browser
   // process to shut it down forcefully instead and wait on the message, so that
   // there are no races between threads when the process is shutting down.
   Send(new WorkerProcessHostMsg_ForceKillWorker());
 }
 
 WorkerThread::~WorkerThread() {
 }
 
 void WorkerThread::Shutdown() {
   ChildThread::Shutdown();
 
   // Shutdown in reverse of the initialization order.
-  channel()->RemoveFilter(indexed_db_message_filter_.get());
+  channel()->RemoveFilter(indexed_db_message_filter_->GetFilter());
   indexed_db_message_filter_ = NULL;
 
   channel()->RemoveFilter(db_message_filter_.get());
   db_message_filter_ = NULL;
 
   blink::shutdown();
   lazy_tls.Pointer()->Set(NULL);
 }
 
 WorkerThread* WorkerThread::current() {
@@ skipping 44 matching lines @@
 
 void WorkerThread::RemoveWorkerStub(WebSharedWorkerStub* stub) {
   worker_stubs_.erase(stub);
 }
 
 void WorkerThread::AddWorkerStub(WebSharedWorkerStub* stub) {
   worker_stubs_.insert(stub);
 }
 
 }  // namespace content