Have content/ create and destroy its own threads.

chrome/browser/browsing_data_file_system_helper_unittest.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 "testing/gtest/include/gtest/gtest.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browsing_data_file_system_helper.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/test/test_browser_thread.h"
 #include "webkit/fileapi/file_system_context.h"
 #include "webkit/fileapi/file_system_path_manager.h"
 #include "webkit/fileapi/file_system_types.h"
 #include "webkit/fileapi/file_system_usage_cache.h"
 #include "webkit/fileapi/sandbox_mount_point_provider.h"
 
@@ skipping 261 matching lines @@
   info++;
   EXPECT_EQ(kOrigin2, info->origin);
   EXPECT_FALSE(info->has_persistent);
   EXPECT_TRUE(info->has_temporary);
   EXPECT_EQ(0, info->usage_persistent);
   EXPECT_EQ(100, info->usage_temporary);
 }
 
 }  // namespace