Automated IWYU fix for TaskRunner includes.

chrome/browser/safe_browsing/download_feedback_service_unittest.cc

 // Copyright 2013 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/browser/safe_browsing/download_feedback_service.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/safe_browsing/download_feedback.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/test/mock_download_item.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "net/url_request/url_request_test_util.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using ::testing::_;
@@ skipping 403 matching lines @@
   // was deleted.
   EXPECT_FALSE(base::PathExists(file_path[2]));
 
   // These files should still exist since the FakeDownloadFeedback does not
   // delete them.
   EXPECT_TRUE(base::PathExists(file_path[0]));
   EXPECT_TRUE(base::PathExists(file_path[1]));
 }
 
 }  // namespace safe_browsing