Add a file thread to the renderer process.

chrome/renderer/render_thread.cc

 // Copyright (c) 2010 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/renderer/render_thread.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <vector>
@@ skipping 289 matching lines @@
 RenderThread::~RenderThread() {
   // Wait for all databases to be closed.
   if (web_database_observer_impl_.get())
     web_database_observer_impl_->WaitForAllDatabasesToClose();
 
   // Shutdown in reverse of the initialization order.
   RemoveFilter(db_message_filter_.get());
   db_message_filter_ = NULL;
   RemoveFilter(devtools_agent_filter_.get());
 
+  // Shutdown the file thread if it's running.
+  if (file_thread_.get())
+    file_thread_->Stop();
+
   if (webkit_client_.get())
     WebKit::shutdown();
 
   lazy_tls.Pointer()->Set(NULL);
 
   // TODO(port)
 #if defined(OS_WIN)
   // Clean up plugin channels before this thread goes away.
   PluginChannelBase::CleanupChannels();
   // Don't call COM if the renderer is in the sandbox.
@@ skipping 773 matching lines @@
 }
 
 std::string RenderThread::GetExtensionIdByBrowseExtent(const GURL& url) {
   for (size_t i = 0; i < extension_extents_.size(); ++i) {
     if (extension_extents_[i].browse_extent.ContainsURL(url))
       return extension_extents_[i].extension_id;
   }
 
   return std::string();
 }
+
+scoped_refptr<base::MessageLoopProxy>
+RenderThread::GetFileThreadMessageLoopProxy() {
+  DCHECK(message_loop() == MessageLoop::current());
+  if (!file_thread_.get()) {
+    file_thread_.reset(new base::Thread("Renderer::FILE"));
+    file_thread_->Start();
+  }
+  return file_thread_->message_loop_proxy();
+}