Automated IWYU fix for TaskRunner includes.

content/browser/fileapi/browser_file_system_helper_unittest.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 <memory>
 #include <string>
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
+#include "base/single_thread_task_runner.h"
 #include "base/test/null_task_runner.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/fileapi/browser_file_system_helper.h"
 #include "content/public/common/drop_data.h"
 #include "net/base/filename_util.h"
 #include "storage/browser/fileapi/external_mount_points.h"
 #include "storage/browser/fileapi/file_system_options.h"
 #include "storage/browser/fileapi/file_system_url.h"
 #include "storage/browser/fileapi/isolated_context.h"
 #include "storage/common/fileapi/file_system_types.h"
@@ skipping 157 matching lines @@
   // Verify that there is still no access for |kOtherFile|.
   EXPECT_FALSE(p->CanReadFile(kRendererID, kOtherFile));
   EXPECT_FALSE(p->CanCreateReadWriteFile(kRendererID, kOtherFile));
   EXPECT_FALSE(
       p->CanCommitURL(kRendererID, net::FilePathToFileURL(kOtherFile)));
 
   p->Remove(kRendererID);
 }
 
 }  // namespace content