[Smart Lock, Prefs reconciliation] Prefs migration logic for desktop platforms.

chrome/browser/password_manager/password_manager_setting_migrator_service.cc

Index: chrome/browser/password_manager/password_manager_setting_migrator_service.cc
diff --git a/chrome/browser/password_manager/password_manager_setting_migrator_service.cc b/chrome/browser/password_manager/password_manager_setting_migrator_service.cc
new file mode 100644
index 0000000000000000000000000000000000000000..301b1367abeaa1edac95534be76ed55cad8e75f5
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+++ b/chrome/browser/password_manager/password_manager_setting_migrator_service.cc
@@ -0,0 +1,233 @@
+// 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.
+
+#include "chrome/browser/password_manager/password_manager_setting_migrator_service.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/prefs/pref_service_syncable_util.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/sync/profile_sync_service.h"
+#include "chrome/browser/sync/profile_sync_service_factory.h"
+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+#include "components/password_manager/core/browser/password_manager_settings_migration_experiment.h"
+#include "components/password_manager/core/common/password_manager_pref_names.h"
+#include "components/syncable_prefs/pref_service_syncable.h"
+#include "content/public/browser/notification_source.h"
+
+namespace {
+
+bool GetBooleanUserOrDefaultPrefValue(PrefService* prefs,
+                                      const std::string& name) {
+  bool result = false;
+  const base::Value* value = prefs->GetUserPrefValue(name);
+  if (!value)
+    value = prefs->GetDefaultPrefValue(name);
+  value->GetAsBoolean(&result);
+  return result;
+}
+
+void ChangeOnePrefBecauseAnotherPrefHasChanged(
+    PrefService* prefs,
+    const std::string& other_pref_name,
+    const std::string& changed_pref_name) {
+  bool changed_pref =
+      GetBooleanUserOrDefaultPrefValue(prefs, changed_pref_name);
+  bool other_pref = GetBooleanUserOrDefaultPrefValue(prefs, other_pref_name);
+  if (changed_pref != other_pref)
+    prefs->SetBoolean(other_pref_name, changed_pref);
+  // TODO(melandory): add histograms in order to track when we can stop
+  // migration.
+}
+
+// Change value of both kPasswordManagerSavingEnabled and
+// kCredentialsEnableService to the |new_value|.
+void UpdatePreferencesValues(PrefService* prefs, bool new_value) {
+  prefs->SetBoolean(password_manager::prefs::kPasswordManagerSavingEnabled,
+                    new_value);
+  prefs->SetBoolean(password_manager::prefs::kCredentialsEnableService,
+                    new_value);
+}
+
+void SaveCurrentPrefState(PrefService* prefs,
+                          bool* new_pref_value,
+                          bool* legacy_pref_value) {
+  *new_pref_value = GetBooleanUserOrDefaultPrefValue(
+      prefs, password_manager::prefs::kCredentialsEnableService);
+  *legacy_pref_value = GetBooleanUserOrDefaultPrefValue(
+      prefs, password_manager::prefs::kPasswordManagerSavingEnabled);
+}
+
+}  // namespace
+
+// static
+PasswordManagerSettingMigratorService::Factory*
+PasswordManagerSettingMigratorService::Factory::GetInstance() {
+  return base::Singleton<PasswordManagerSettingMigratorService::Factory>::get();
+}
+
+// static
+PasswordManagerSettingMigratorService*
+PasswordManagerSettingMigratorService::Factory::GetForProfile(
+    Profile* profile) {
+  return static_cast<PasswordManagerSettingMigratorService*>(
+      GetInstance()->GetServiceForBrowserContext(profile, true));
+}
+
+PasswordManagerSettingMigratorService::Factory::Factory()
+    : BrowserContextKeyedServiceFactory(
+          "PasswordManagerSettingMigratorService",
+          BrowserContextDependencyManager::GetInstance()) {
+  DependsOn(ProfileSyncServiceFactory::GetInstance());
+}
+
+PasswordManagerSettingMigratorService::Factory::~Factory() {}
+
+KeyedService*
+PasswordManagerSettingMigratorService::Factory::BuildServiceInstanceFor(
+    content::BrowserContext* context) const {
+  return new PasswordManagerSettingMigratorService(
+      Profile::FromBrowserContext(context));
+}
+
+bool PasswordManagerSettingMigratorService::Factory::
+    ServiceIsCreatedWithBrowserContext() const {
+  return true;
+}
+
+PasswordManagerSettingMigratorService::PasswordManagerSettingMigratorService(
+    Profile* profile)
+    : profile_(profile), sync_service_(nullptr) {
+  SaveCurrentPrefState(profile->GetPrefs(), &initial_new_pref_value_,
+                       &initial_legacy_pref_value_);
+  // If there will be a ProfileSyncService, the rest of the initialization
+  // should take place after that service is created. The ProfileSyncService is
+  // normally created before NOTIFICATION_PROFILE_ADDED, so defer the rest of
+  // the initialization until after that.
+  registrar_.Add(this, chrome::NOTIFICATION_PROFILE_ADDED,
+                 content::Source<Profile>(profile));
+}
+
+PasswordManagerSettingMigratorService::
+    ~PasswordManagerSettingMigratorService() {}
+
+void PasswordManagerSettingMigratorService::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  DCHECK_EQ(chrome::NOTIFICATION_PROFILE_ADDED, type);
+  SaveCurrentPrefState(profile_->GetPrefs(), &initial_new_pref_value_,
+                       &initial_legacy_pref_value_);
+  if (!password_manager::IsSettingsMigrationActive()) {
+    // TODO(melandory) Add histogram which will log initial values for the both
+    // settings.
+    return;
+  }
+  if (ProfileSyncServiceFactory::HasProfileSyncService(profile_))
+    sync_service_ = ProfileSyncServiceFactory::GetForProfile(profile_);
+  if (!CanSyncStart())
+    MigrateOffState(profile_->GetPrefs());
+  InitObservers();
+}
+
+void PasswordManagerSettingMigratorService::InitObservers() {
+  syncable_prefs::PrefServiceSyncable* prefs =
+      PrefServiceSyncableFromProfile(profile_);
+  pref_change_registrar_.Init(profile_->GetPrefs());
+  pref_change_registrar_.Add(
+      password_manager::prefs::kCredentialsEnableService,
+      base::Bind(&PasswordManagerSettingMigratorService::
+                     OnCredentialsEnableServicePrefChanged,
+                 base::Unretained(this)));
+  pref_change_registrar_.Add(
+      password_manager::prefs::kPasswordManagerSavingEnabled,
+      base::Bind(&PasswordManagerSettingMigratorService::
+                     OnPasswordManagerSavingEnabledPrefChanged,
+                 base::Unretained(this)));
+  // This causes OnIsSyncingChanged to be called when the value of
+  // PrefService::IsSyncing() changes.
+  prefs->AddObserver(this);
+}
+
+bool PasswordManagerSettingMigratorService::CanSyncStart() {
+  return sync_service_ && sync_service_->CanSyncStart() &&
+         syncer::UserSelectableTypes().Has(syncer::PREFERENCES);
+}
+
+void PasswordManagerSettingMigratorService::Shutdown() {
+  syncable_prefs::PrefServiceSyncable* prefs =
+      PrefServiceSyncableFromProfile(profile_);
+  prefs->RemoveObserver(this);
+}
+
+void PasswordManagerSettingMigratorService::
+    OnCredentialsEnableServicePrefChanged(
+        const std::string& changed_pref_name) {
+  PrefService* prefs = profile_->GetPrefs();
+  sync_data_.push_back(GetBooleanUserOrDefaultPrefValue(
+      prefs, password_manager::prefs::kCredentialsEnableService));
+  ChangeOnePrefBecauseAnotherPrefHasChanged(
+      prefs, password_manager::prefs::kPasswordManagerSavingEnabled,
+      password_manager::prefs::kCredentialsEnableService);
+}
+
+void PasswordManagerSettingMigratorService::
+    OnPasswordManagerSavingEnabledPrefChanged(
+        const std::string& changed_pref_name) {
+  PrefService* prefs = profile_->GetPrefs();
+  sync_data_.push_back(GetBooleanUserOrDefaultPrefValue(
+      prefs, password_manager::prefs::kPasswordManagerSavingEnabled));
+  ChangeOnePrefBecauseAnotherPrefHasChanged(
+      prefs, password_manager::prefs::kCredentialsEnableService,
+      password_manager::prefs::kPasswordManagerSavingEnabled);
+}
+
+void PasswordManagerSettingMigratorService::OnIsSyncingChanged() {
+  syncable_prefs::PrefServiceSyncable* prefs =
+      PrefServiceSyncableFromProfile(profile_);
+  if (prefs->IsSyncing() && prefs->IsPrioritySyncing()) {
+    // Initial sync has finished.
+    MigrateAfterModelAssociation(prefs);
+  }
+
+  if (prefs->IsSyncing() == prefs->IsPrioritySyncing()) {
+    // Sync is not in model association step.
+    SaveCurrentPrefState(prefs, &initial_new_pref_value_,
+                         &initial_legacy_pref_value_);
+    sync_data_.clear();
+  }
+}
+
+void PasswordManagerSettingMigratorService::MigrateOffState(
+    PrefService* prefs) {
+  bool new_pref_value = GetBooleanUserOrDefaultPrefValue(
+      prefs, password_manager::prefs::kCredentialsEnableService);
+  bool legacy_pref_value = GetBooleanUserOrDefaultPrefValue(
+      prefs, password_manager::prefs::kPasswordManagerSavingEnabled);
+  UpdatePreferencesValues(prefs, new_pref_value && legacy_pref_value);
+}
+
+void PasswordManagerSettingMigratorService::MigrateAfterModelAssociation(
+    PrefService* prefs) {
+  if (sync_data_.empty()) {
+    MigrateOffState(prefs);
+  } else if (sync_data_.size() == 1) {
+    // Only one value came from sync. This value should be assigned to both
+    // preferences.
+    UpdatePreferencesValues(prefs, sync_data_[0]);
+  } else {
+    bool sync_new_pref_value = sync_data_[0];
+    bool sync_legacy_pref_value = sync_data_.back();
+    if (sync_legacy_pref_value && sync_new_pref_value) {
+      UpdatePreferencesValues(prefs, true);
+    } else if (!sync_legacy_pref_value && !sync_new_pref_value) {
+      UpdatePreferencesValues(prefs, false);
+    } else if (!initial_legacy_pref_value_ && !initial_new_pref_value_) {
+      UpdatePreferencesValues(prefs, true);
+    } else {
+      UpdatePreferencesValues(prefs, false);
+    }
+  }
+}