Replace deprecated base::NonThreadSafe in components/prefs in favor of SequenceChecker.

components/prefs/scoped_user_pref_update.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.
 //
 // A helper class that assists preferences in firing notifications when lists
 // or dictionaries are changed.
 
 #ifndef COMPONENTS_PREFS_SCOPED_USER_PREF_UPDATE_H_
 #define COMPONENTS_PREFS_SCOPED_USER_PREF_UPDATE_H_
 
 #include <string>
 
 #include "base/macros.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "base/values.h"
 #include "components/prefs/base_prefs_export.h"
 #include "components/prefs/pref_service.h"
 
 class PrefService;
 
 namespace base {
 class DictionaryValue;
 class ListValue;
 }
 
 namespace subtle {
 
 // Base class for ScopedUserPrefUpdateTemplate that contains the parts
 // that do not depend on ScopedUserPrefUpdateTemplate's template parameter.
 //
 // We need this base class mostly for making it a friend of PrefService
 // and getting access to PrefService::GetMutableUserPref and
 // PrefService::ReportUserPrefChanged.
-class COMPONENTS_PREFS_EXPORT ScopedUserPrefUpdateBase
-    : public base::NonThreadSafe {
+class COMPONENTS_PREFS_EXPORT ScopedUserPrefUpdateBase {
  protected:
   ScopedUserPrefUpdateBase(PrefService* service, const std::string& path);
 
   // Calls Notify().
   ~ScopedUserPrefUpdateBase();
 
   // Sets |value_| to |service_|->GetMutableUserPref and returns it.
   base::Value* GetValueOfType(base::Value::Type type);
 
  private:
   // If |value_| is not null, triggers a notification of PrefObservers and
   // resets |value_|.
   void Notify();
 
   // Weak pointer.
   PrefService* service_;
   // Path of the preference being updated.
   std::string path_;
   // Cache of value from user pref store (set between Get() and Notify() calls).
   base::Value* value_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(ScopedUserPrefUpdateBase);
 };
 
 }  // namespace subtle
 
 // Class to support modifications to DictionaryValues and ListValues while
 // guaranteeing that PrefObservers are notified of changed values.
 //
 // This class may only be used on the UI thread as it requires access to the
 // PrefService.
@@ skipping 33 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(ScopedUserPrefUpdate);
 };
 
 typedef ScopedUserPrefUpdate<base::DictionaryValue,
                              base::Value::Type::DICTIONARY>
     DictionaryPrefUpdate;
 typedef ScopedUserPrefUpdate<base::ListValue, base::Value::Type::LIST>
     ListPrefUpdate;
 
 #endif  // COMPONENTS_PREFS_SCOPED_USER_PREF_UPDATE_H_