Introduce a new framework for back-and-forth tracked/protected preferences migration.

chrome/browser/prefs/profile_pref_store_manager.h

 // Copyright 2014 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_PREFS_PROFILE_PREF_STORE_MANAGER_H_
 #define CHROME_BROWSER_PREFS_PROFILE_PREF_STORE_MANAGER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 90 matching lines @@
   // Creates a single-file PrefStore as was used in M34 and earlier. Used only
   // for testing migration.
   PersistentPrefStore* CreateDeprecatedCombinedProfilePrefStore(
       const scoped_refptr<base::SequencedTaskRunner>& io_task_runner);
 
  private:
   // Returns a PrefHashStoreImpl for the managed profile. Should only be called
   // if |kPlatformSupportsPreferenceTracking|.
   scoped_ptr<PrefHashStoreImpl> GetPrefHashStoreImpl();
 
-  // Returns a PrefHashStore that is a copy of the current state of the real
-  // hash store.
-  scoped_ptr<PrefHashStore> CopyPrefHashStore();
-
   const base::FilePath profile_path_;
   const std::vector<PrefHashFilter::TrackedPreferenceMetadata>
       tracking_configuration_;
   const size_t reporting_ids_count_;
   const std::string seed_;
   const std::string device_id_;
   PrefService* local_state_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfilePrefStoreManager);
 };
 
 #endif  // CHROME_BROWSER_PREFS_PROFILE_PREF_STORE_MANAGER_H_