[Smart Lock, Prefs reconciliation] Finished componetization.

chrome/browser/password_manager/password_manager_setting_migrator_service.h

Index: chrome/browser/password_manager/password_manager_setting_migrator_service.h
diff --git a/chrome/browser/password_manager/password_manager_setting_migrator_service.h b/chrome/browser/password_manager/password_manager_setting_migrator_service.h
deleted file mode 100644
index ce389deedf0be74d55fdf7a47e2998f56748a24a..0000000000000000000000000000000000000000
--- a/chrome/browser/password_manager/password_manager_setting_migrator_service.h
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@@ -1,154 +0,0 @@
-// Copyright (c) 2015 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_PASSWORD_MANAGER_PASSWORD_MANAGER_SETTING_MIGRATOR_SERVICE_H_
-#define CHROME_BROWSER_PASSWORD_MANAGER_PASSWORD_MANAGER_SETTING_MIGRATOR_SERVICE_H_
-
-#include <vector>
-
-#include "base/memory/singleton.h"
-#include "base/prefs/pref_change_registrar.h"
-#include "components/keyed_service/content/browser_context_keyed_service_factory.h"
-#include "components/keyed_service/core/keyed_service.h"
-#include "components/syncable_prefs/pref_service_syncable_observer.h"
-
-namespace sync_driver {
-class SyncService;
-}
-
-namespace syncable_prefs {
-class PrefServiceSyncable;
-}
-
-namespace password_manager {
-
-// Service that is responsible for reconciling the legacy "Offer to save your
-// web passwords" setting (henceforth denoted 'L', for legacy) with the new
-// "Enable Smart Lock for Passwords" setting (henceforth denoted 'N', for new).
-//
-// It works as follows.
-//
-// Users who are not syncing (this is checked on start-up of the service
-// calling to SyncService:CanSyncStart()) are migrated on startup of the
-// service. These users can be in following states:
-//   1. N = 0, L = 0
-//   2. N = 1, L = 1
-//   3. N = 1, L = 0
-//   4. N = 0, L = 1
-//
-// Nothing should be done in case 1 and 2 since settings are already in sync;
-// in case 3,4 we change value of N to 0.
-//
-// For users who are syncing we save the values for the new and legacy
-// preference on service startup (|inital_values_|) and the values that come
-// from sync during models association step (|sync_data_|). Propagating change
-// of one preference to another preference without having this special treatment
-// will not always work. Here is an example which illustrates possible corner
-// case: the client executes the migration code for the first time, legacy
-// preference has a value 1, new preference was registered for the
-// first time and has default value which is also 1, the sync data snapshot
-// which user has on a client contains new preference equal to 0 and old
-// preference equal to 1, if we blindly propagate these values we first get
-// both preferences equal to 0 after priority pref model was associated and
-// then both preferences equal to 1 after preferences model was associated.
-// But the correct final value in this case is 0.
-//
-// At the end of model association step we derive the new values for both
-// settings using the following table (first column contains local values for
-// the preferences, first row contains values which came from sync, where _
-// means that the value did not come):
-//
-//  NL*  0_  1_  _0  _1  00  01  10  11
-//
-//  00   00  11  00  11  00  11  11  11
-//  01   00* 11* x   x   00  00  00  11
-//  10   00* 00* x   x   00  00  00  11
-//  11   00  11  00  11  00  00  00  11
-//
-//  *these cases only possible on mobile platforms, where we sync only priority
-//  preference data type.
-//
-// The service observes changes to both preferences (e.g. changes from sync,
-// changes from UI) and propagates the change to the other preference if needed.
-//
-// Note: componetization of this service currently is impossible, because it
-// depends on PrefServiceSyncable https://crbug.com/522536.
-class PasswordManagerSettingMigratorService
-    : public KeyedService,
-      public syncable_prefs::PrefServiceSyncableObserver {
- public:
-  explicit PasswordManagerSettingMigratorService(
-      syncable_prefs::PrefServiceSyncable* prefs);
-  ~PasswordManagerSettingMigratorService() override;
-
-  void Shutdown() override;
-
-  // PrefServiceSyncableObserver:
-  void OnIsSyncingChanged() override;
-
-  void InitializeMigration(sync_driver::SyncService* sync_service);
-
- private:
-  // Initializes the observers: preferences observers and sync status observers.
-  void InitObservers();
-
-  // Returns true if sync is expected to start for the user.
-  bool CanSyncStart();
-
-  // Called when the value of the |kCredentialsEnableService| preference
-  // changes, and updates the value of |kPasswordManagerSavingEnabled|
-  // preference accordingly.
-  void OnCredentialsEnableServicePrefChanged(
-      const std::string& changed_pref_name);
-
-  // Called when the value of the |kPasswordManagerSavingEnabled| preference
-  // changes, and updates the value of |kCredentialsEnableService| preference
-  // accordingly.
-  void OnPasswordManagerSavingEnabledPrefChanged(
-      const std::string& changed_pref_name);
-
-  // Determines if model association step was performed. For desktop platforms,
-  // the condition is that for both priority preferences and regular preferences
-  // types association step was finished. For mobile platforms, the association
-  // only for priority prefs is required.
-  bool WasModelAssociationStepPerformed();
-
-  // Turns off one pref if another pref is off.
-  void MigrateOffState(PrefService* prefs);
-
-  // Performs a migration after sync associates models. Migration is performed
-  // based on initial values for both preferences and values received from
-  // sync.
-  void MigrateAfterModelAssociation(PrefService* prefs);
-
-  // Contains values which have come from sync during model association step.
-  // The vector minimum size is 0 and the vector maximum size is 4:
-  //   * sync_data_ has length equal to 0, when no change to the preferences has
-  //   came from sync.
-  //   * sync_data has length equal to 1, when change to only one preference
-  //   came from sync and another pref already had this value, e.g local state
-  //   01 and N=1 came from sync.
-  //   * sync_data has length equals to 4, changes to both preference has came
-  //   from sync, e.g. local state is 11 and 01 came from sync.
-  // This way index 0 corresponds to kCredentialsEnableService, last index
-  // corresponds to kPasswordManagerSavingEnabled if size of sync_data_ equals
-  // to 4, otherwise the vector contains the value only for one preference.
-  std::vector<bool> sync_data_;
-
-  // The initial value for kCredentialsEnableService.
-  bool initial_new_pref_value_;
-  // The initial value for kPasswordManagerSavingEnabled.
-  bool initial_legacy_pref_value_;
-
-  syncable_prefs::PrefServiceSyncable* prefs_;
-  sync_driver::SyncService* sync_service_;
-
-  PrefChangeRegistrar pref_change_registrar_;
-
-  DISALLOW_COPY_AND_ASSIGN(PasswordManagerSettingMigratorService);
-};
-
-}  // namespace password_manager
-
-#endif  // CHROME_BROWSER_PASSWORD_MANAGER_PASSWORD_MANAGER_SETTING_MIGRATOR_SERVICE_H_