Create a secondary file thread, FILE_USER_BLOCKING...

chrome/test/base/testing_browser_process.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/test/base/testing_browser_process.h"
 
 #include "base/string_util.h"
 #include "chrome/browser/google/google_url_tracker.h"
 #include "chrome/browser/notifications/notification_ui_manager.h"
 #include "chrome/browser/policy/browser_policy_connector.h"
@@ skipping 25 matching lines @@
 }
 
 MetricsService* TestingBrowserProcess::metrics_service() {
   return NULL;
 }
 
 IOThread* TestingBrowserProcess::io_thread() {
   return io_thread_;
 }
 
+base::Thread* TestingBrowserProcess::file_user_blocking_thread() {
+  return NULL;
+}
+
 base::Thread* TestingBrowserProcess::file_thread() {
   return NULL;
 }
 
 base::Thread* TestingBrowserProcess::db_thread() {
   return NULL;
 }
 
 base::Thread* TestingBrowserProcess::cache_thread() {
   return NULL;
@@ skipping 204 matching lines @@
 }
 
 void TestingBrowserProcess::SetIOThread(IOThread* io_thread) {
   io_thread_ = io_thread;
 }
 
 void TestingBrowserProcess::SetBrowserPolicyConnector(
     policy::BrowserPolicyConnector* connector) {
   browser_policy_connector_.reset(connector);
 }