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 "base/sequence_checker.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 {

[Nathan Parker, 2017/05/30 17:16:47]

NonThreadSafe was removed, but no SequenceChecker was added here.

[gab, 2017/05/30 21:54:00]

Forgot to say in CL description but I found a few like this one where the impl
didn't use any NonThreadSafe methods... so I guess it was merely verifying on
destruction... unless the destructor was more crucial than anything, I'll leave
it up to the OWNERS to add missing checks.

[Nathan Parker, 2017/06/01 18:41:44]

I'm confused -- Why not add DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_)
to the dtor, like you did for the other file?  That way this retains the dtor
checking.

  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_