Remove the alternative preferences filename from JsonPrefStore.

components/prefs/json_pref_store.h

 // 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.
 
 #ifndef COMPONENTS_PREFS_JSON_PREF_STORE_H_
 #define COMPONENTS_PREFS_JSON_PREF_STORE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 44 matching lines @@
   // to disk.
   using OnWriteCallbackPair =
       std::pair<base::Closure, base::Callback<void(bool success)>>;
 
   // Returns instance of SequencedTaskRunner which guarantees that file
   // operations on the same file will be executed in sequenced order.
   static scoped_refptr<base::SequencedTaskRunner> GetTaskRunnerForFile(
       const base::FilePath& pref_filename,
       base::SequencedWorkerPool* worker_pool);
 
-  // Same as the constructor below with no alternate filename.
+  // |sequenced_task_runner| must be a shutdown-blocking task runner, ideally
+  // created by the GetTaskRunnerForFile() method above.
+  // |pref_filename| is the path to the file to read prefs from.
   JsonPrefStore(
       const base::FilePath& pref_filename,
       const scoped_refptr<base::SequencedTaskRunner>& sequenced_task_runner,
       std::unique_ptr<PrefFilter> pref_filter);
 
-  // |sequenced_task_runner| must be a shutdown-blocking task runner, ideally
-  // created by the GetTaskRunnerForFile() method above.
-  // |pref_filename| is the path to the file to read prefs from.
-  // |pref_alternate_filename| is the path to an alternate file which the
-  // desired prefs may have previously been written to. If |pref_filename|
-  // doesn't exist and |pref_alternate_filename| does, |pref_alternate_filename|
-  // will be moved to |pref_filename| before the read occurs.
-  JsonPrefStore(
-      const base::FilePath& pref_filename,
-      const base::FilePath& pref_alternate_filename,
-      const scoped_refptr<base::SequencedTaskRunner>& sequenced_task_runner,
-      std::unique_ptr<PrefFilter> pref_filter);
-
   // PrefStore overrides:
   bool GetValue(const std::string& key,
                 const base::Value** result) const override;
   std::unique_ptr<base::DictionaryValue> GetValues() const override;
   void AddObserver(PrefStore::Observer* observer) override;
   void RemoveObserver(PrefStore::Observer* observer) override;
   bool HasObservers() const override;
   bool IsInitializationComplete() const override;
 
   // PersistentPrefStore overrides:
@@ skipping 130 matching lines @@
   // this will be ignored if this store is read-only.
   void FinalizeFileRead(bool initialization_successful,
                         std::unique_ptr<base::DictionaryValue> prefs,
                         bool schedule_write);
 
   // Schedule a write with the file writer as long as |flags| doesn't contain
   // WriteablePrefStore::LOSSY_PREF_WRITE_FLAG.
   void ScheduleWrite(uint32_t flags);
 
   const base::FilePath path_;
-  const base::FilePath alternate_path_;
   const scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner_;
 
   std::unique_ptr<base::DictionaryValue> prefs_;
 
   bool read_only_;
 
   // Helper for safely writing pref data.
   base::ImportantFileWriter writer_;
 
   std::unique_ptr<PrefFilter> pref_filter_;
@@ skipping 10 matching lines @@
 
   bool has_pending_write_reply_ = true;
   base::Closure on_next_successful_write_reply_;
 
   WriteCountHistogram write_count_histogram_;
 
   DISALLOW_COPY_AND_ASSIGN(JsonPrefStore);
 };
 
 #endif  // COMPONENTS_PREFS_JSON_PREF_STORE_H_