Replace deprecated base::NonThreadSafe in chrome/browser/safe_browsing in favor of SequenceChecker.

chrome/browser/safe_browsing/download_feedback.h

 // 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.
 
 #ifndef CHROME_BROWSER_SAFE_BROWSING_DOWNLOAD_FEEDBACK_H_
 #define CHROME_BROWSER_SAFE_BROWSING_DOWNLOAD_FEEDBACK_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/files/file_path.h"
-#include "base/threading/non_thread_safe.h"
 #include "chrome/browser/safe_browsing/two_phase_uploader.h"
 
 namespace safe_browsing {
 
 class DownloadFeedbackFactory;
 
 // Handles the uploading of a single downloaded binary to the safebrowsing
 // download feedback service.
-class DownloadFeedback : public base::NonThreadSafe {
+class DownloadFeedback {
  public:
   // Takes ownership of the file pointed to be |file_path|, it will be deleted
   // when the DownloadFeedback is destructed.
   static std::unique_ptr<DownloadFeedback> Create(
       net::URLRequestContextGetter* request_context_getter,
       base::TaskRunner* file_task_runner,
       const base::FilePath& file_path,
       const std::string& ping_request,
       const std::string& ping_response);
 
@@ skipping 36 matching lines @@
       net::URLRequestContextGetter* request_context_getter,
       base::TaskRunner* file_task_runner,
       const base::FilePath& file_path,
       const std::string& ping_request,
       const std::string& ping_response) = 0;
 };
 
 }  // namespace safe_browsing
 
 #endif  // CHROME_BROWSER_SAFE_BROWSING_DOWNLOAD_FEEDBACK_H_