Register Chrome OS syncable prefs as SYNCABLE_OS_PREF

Historically OS settings were synced as part of the browser settings
model type. The go/split-settings-sync project is migrating them to
a new model type, with separate UI controls.

Update all the OS pref registration sites to use registration flags
SYNCABLE_OS_PREF and SYNCABLE_OS_PRIORITY_PREF. The prefs were
found by manually auditing all pref registration.

If the SplitSettingsSync flag is disabled, these prefs are synced as
they were before, using the old syncer::ModelType. See the flag
check in //components/sync_preferences/pref_service_syncable.cc

Fix PrefRegistrySyncable so it runs the registration callback for
OS prefs as well as browser prefs.

Bug: 1013466
Change-Id: Ie0ba1244a74e300c3292252a83b30768d1644720
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1866927
Commit-Queue: James Cook <jamescook@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Reviewed-by: Jia Meng <jiameng@chromium.org>
Reviewed-by: Stefan Kuhne <skuhne@chromium.org>
Reviewed-by: Dominic Battré <battre@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708482}

ash/accessibility/accessibility_controller_impl.cc

@@ -269,104 +269,107 @@ void AccessibilityControllerImpl::RegisterProfilePrefs(
     PrefRegistrySimple* registry) {
   registry->RegisterBooleanPref(
       prefs::kAccessibilityAutoclickEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kAccessibilityAutoclickDelayMs, kDefaultAutoclickDelayMs,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kAccessibilityAutoclickEventType,
       static_cast<int>(kDefaultAutoclickEventType),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityAutoclickRevertToLeftClick, true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityAutoclickStabilizePosition, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kAccessibilityAutoclickMovementThreshold,
       kDefaultAutoclickMovementThreshold,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kAccessibilityAutoclickMenuPosition,
       static_cast<int>(kDefaultAutoclickMenuPosition),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityCaretHighlightEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityCursorHighlightEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityDictationEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityFocusHighlightEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityHighContrastEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityLargeCursorEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(prefs::kAccessibilityLargeCursorDipSize,
                                 kDefaultLargeCursorSize);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityMonoAudioEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityScreenMagnifierCenterFocus, true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityScreenMagnifierEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterDoublePref(prefs::kAccessibilityScreenMagnifierScale,
                                std::numeric_limits<double>::min());
   registry->RegisterBooleanPref(prefs::kAccessibilitySpokenFeedbackEnabled,
                                 false);
   registry->RegisterBooleanPref(
       prefs::kAccessibilitySelectToSpeakEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityStickyKeysEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilitySwitchAccessEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
-  registry->RegisterListPref(prefs::kAccessibilitySwitchAccessSelectKeyCodes,
-                             base::Value(std::vector<base::Value>()),
-                             user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
+  registry->RegisterListPref(
+      prefs::kAccessibilitySwitchAccessSelectKeyCodes,
+      base::Value(std::vector<base::Value>()),
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kAccessibilitySwitchAccessSelectSetting,
       kSwitchAccessAssignmentNone,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
-  registry->RegisterListPref(prefs::kAccessibilitySwitchAccessNextKeyCodes,
-                             base::Value(std::vector<base::Value>()),
-                             user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
+  registry->RegisterListPref(
+      prefs::kAccessibilitySwitchAccessNextKeyCodes,
+      base::Value(std::vector<base::Value>()),
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kAccessibilitySwitchAccessNextSetting, kSwitchAccessAssignmentNone,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
-  registry->RegisterListPref(prefs::kAccessibilitySwitchAccessPreviousKeyCodes,
-                             base::Value(std::vector<base::Value>()),
-                             user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
+  registry->RegisterListPref(
+      prefs::kAccessibilitySwitchAccessPreviousKeyCodes,
+      base::Value(std::vector<base::Value>()),
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kAccessibilitySwitchAccessPreviousSetting,
       kSwitchAccessAssignmentNone,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilitySwitchAccessAutoScanEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kAccessibilitySwitchAccessAutoScanSpeedMs,
       kDefaultSwitchAccessAutoScanSpeed.InMilliseconds(),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kAccessibilitySwitchAccessAutoScanKeyboardSpeedMs,
       kDefaultSwitchAccessAutoScanSpeed.InMilliseconds(),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kAccessibilityVirtualKeyboardEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kHighContrastAcceleratorDialogHasBeenAccepted, false);
   registry->RegisterBooleanPref(
@@ -380,7 +383,7 @@ void AccessibilityControllerImpl::RegisterProfilePrefs(
 
   registry->RegisterBooleanPref(
       prefs::kShouldAlwaysShowAccessibilityMenu, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 }
 
 void AccessibilityControllerImpl::Shutdown() {

ash/app_list/app_list_controller_impl.cc

@@ -179,7 +179,7 @@ void AppListControllerImpl::RegisterProfilePrefs(PrefRegistrySimple* registry) {
   registry->RegisterIntegerPref(prefs::kAssistantPrivacyInfoShownInLauncher, 0);
   registry->RegisterBooleanPref(
       prefs::kAssistantPrivacyInfoDismissedInLauncher, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 }
 
 void AppListControllerImpl::SetClient(AppListClient* client) {

ash/shelf/shelf_controller.cc

@@ -126,13 +126,14 @@ void ShelfController::RegisterProfilePrefs(PrefRegistrySimple* registry) {
   // These prefs are public for ChromeLauncherController's OnIsSyncingChanged.
   // See the pref names definitions for explanations of the synced, local, and
   // per-display behaviors.
-  registry->RegisterStringPref(prefs::kShelfAutoHideBehavior,
-                               kShelfAutoHideBehaviorNever,
-                               user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterStringPref(
+      prefs::kShelfAutoHideBehavior, kShelfAutoHideBehaviorNever,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterStringPref(prefs::kShelfAutoHideBehaviorLocal,
                                std::string());
-  registry->RegisterStringPref(prefs::kShelfAlignment, kShelfAlignmentBottom,
-                               user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterStringPref(
+      prefs::kShelfAlignment, kShelfAlignmentBottom,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterStringPref(prefs::kShelfAlignmentLocal, std::string());
   registry->RegisterDictionaryPref(prefs::kShelfPreferences);
 }

ash/system/message_center/message_center_controller.cc

@@ -34,9 +34,10 @@ namespace ash {
 // static
 void MessageCenterController::RegisterProfilePrefs(
     PrefRegistrySimple* registry) {
-  registry->RegisterStringPref(prefs::kMessageCenterLockScreenMode,
-                               prefs::kMessageCenterLockScreenModeHide,
-                               user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterStringPref(
+      prefs::kMessageCenterLockScreenMode,
+      prefs::kMessageCenterLockScreenModeHide,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 }
 
 namespace {

ash/system/palette/palette_tray.cc

@@ -212,10 +212,10 @@ void PaletteTray::RegisterLocalStatePrefs(PrefRegistrySimple* registry) {
 void PaletteTray::RegisterProfilePrefs(PrefRegistrySimple* registry) {
   registry->RegisterBooleanPref(
       prefs::kEnableStylusTools, true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kLaunchPaletteOnEjectEvent, true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 }
 
 bool PaletteTray::ContainsPointInScreen(const gfx::Point& point) {

ash/system/power/power_prefs.cc

@@ -108,7 +108,7 @@ void RegisterProfilePrefs(PrefRegistrySimple* registry) {
   registry->RegisterBooleanPref(prefs::kAllowScreenLock, true);
   registry->RegisterBooleanPref(
       prefs::kEnableAutoScreenLock, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 }
 
 }  // namespace

ash/touch/touch_devices_controller.cc

@@ -36,7 +36,7 @@ void TouchDevicesController::RegisterProfilePrefs(
     PrefRegistrySimple* registry) {
   registry->RegisterBooleanPref(
       prefs::kTapDraggingEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterBooleanPref(prefs::kTouchpadEnabled, true);
   registry->RegisterBooleanPref(prefs::kTouchscreenEnabled, true);
 }

chrome/browser/chromeos/input_method/input_method_syncer.cc

@@ -126,11 +126,11 @@ InputMethodSyncer::~InputMethodSyncer() {
 void InputMethodSyncer::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterStringPref(
-      prefs::kLanguagePreloadEnginesSyncable,
-      "",
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
-  registry->RegisterStringPref(prefs::kLanguageEnabledImesSyncable, "",
-                               user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      prefs::kLanguagePreloadEnginesSyncable, "",
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
+  registry->RegisterStringPref(
+      prefs::kLanguageEnabledImesSyncable, "",
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(prefs::kLanguageShouldMergeInputMethods, false);
 }
 

chrome/browser/chromeos/login/users/avatar/user_image_sync_observer.cc

@@ -65,7 +65,8 @@ UserImageSyncObserver::~UserImageSyncObserver() {
 void UserImageSyncObserver::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry_) {
   registry_->RegisterDictionaryPref(
-      kUserImageInfo, user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      kUserImageInfo,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
 }
 
 void UserImageSyncObserver::OnProfileGained(Profile* profile) {

chrome/browser/chromeos/login/users/multi_profile_user_controller.cc

@@ -76,10 +76,10 @@ void MultiProfileUserController::RegisterProfilePrefs(
                                kBehaviorUnrestricted);
   registry->RegisterBooleanPref(
       prefs::kMultiProfileNeverShowIntro, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       prefs::kMultiProfileWarningShowDismissed, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 }
 
 // static

chrome/browser/chromeos/preferences.cc

@@ -190,55 +190,51 @@ void Preferences::RegisterProfilePrefs(
       prefs::kAccountManagerNumTimesWelcomeScreenShown, 0 /* default_value */);
 
   registry->RegisterBooleanPref(
-      prefs::kTapToClickEnabled,
-      true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      prefs::kTapToClickEnabled, true,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterBooleanPref(prefs::kEnableTouchpadThreeFingerClick, false);
   // This preference can only be set to true by policy or command_line flag
   // and it should not carry over to sessions were neither of these is set.
   registry->RegisterBooleanPref(prefs::kUnifiedDesktopEnabledByDefault, false,
                                 PrefRegistry::NO_REGISTRATION_FLAGS);
   registry->RegisterBooleanPref(
-      prefs::kNaturalScroll, base::CommandLine::ForCurrentProcess()->HasSwitch(
-                                 switches::kNaturalScrollDefault),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      prefs::kNaturalScroll,
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kNaturalScrollDefault),
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterBooleanPref(
-      prefs::kPrimaryMouseButtonRight,
-      false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      prefs::kPrimaryMouseButtonRight, false,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterBooleanPref(
       prefs::kMouseReverseScroll, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterBooleanPref(
       prefs::kMouseAcceleration, true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterBooleanPref(
       prefs::kTouchpadAcceleration, true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterBooleanPref(prefs::kLabsMediaplayerEnabled, false);
   registry->RegisterBooleanPref(prefs::kLabsAdvancedFilesystemEnabled, false);
   registry->RegisterBooleanPref(prefs::kAppReinstallRecommendationEnabled,
                                 false);
 
   registry->RegisterIntegerPref(
-      prefs::kMouseSensitivity,
-      3,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      prefs::kMouseSensitivity, 3,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterIntegerPref(
-      prefs::kTouchpadSensitivity,
-      3,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      prefs::kTouchpadSensitivity, 3,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterBooleanPref(
-      prefs::kUse24HourClock,
-      base::GetHourClockType() == base::k24HourClock,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      prefs::kUse24HourClock, base::GetHourClockType() == base::k24HourClock,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(prefs::kCameraMediaConsolidated, false);
   registry->RegisterBooleanPref(
       drive::prefs::kDisableDrive, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(
       drive::prefs::kDisableDriveOverCellular, true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(drive::prefs::kDriveFsWasLaunchedAtLeastOnce,
                                 false);
   registry->RegisterStringPref(drive::prefs::kDriveFsProfileSalt, "");
@@ -257,19 +253,19 @@ void Preferences::RegisterProfilePrefs(
   registry->RegisterIntegerPref(
       prefs::kLanguageRemapSearchKeyTo,
       static_cast<int>(ui::chromeos::ModifierKey::kSearchKey),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterIntegerPref(
       prefs::kLanguageRemapControlKeyTo,
       static_cast<int>(ui::chromeos::ModifierKey::kControlKey),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterIntegerPref(
       prefs::kLanguageRemapAltKeyTo,
       static_cast<int>(ui::chromeos::ModifierKey::kAltKey),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterIntegerPref(
       prefs::kLanguageRemapAssistantKeyTo,
       static_cast<int>(ui::chromeos::ModifierKey::kAssistantKey),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   // We don't sync the CapsLock remapping pref, since the UI hides this pref
   // on certain devices, so syncing a non-default value to a device that
   // doesn't allow changing the pref would be odd. http://crbug.com/167237
@@ -279,23 +275,23 @@ void Preferences::RegisterProfilePrefs(
   registry->RegisterIntegerPref(
       prefs::kLanguageRemapEscapeKeyTo,
       static_cast<int>(ui::chromeos::ModifierKey::kEscapeKey),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterIntegerPref(
       prefs::kLanguageRemapBackspaceKeyTo,
       static_cast<int>(ui::chromeos::ModifierKey::kBackspaceKey),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   // The Command key on external Apple keyboards is remapped by default to Ctrl
   // until the user changes it from the keyboard settings.
   registry->RegisterIntegerPref(
       prefs::kLanguageRemapExternalCommandKeyTo,
       static_cast<int>(ui::chromeos::ModifierKey::kControlKey),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   // The Meta key (Search or Windows keys) on external keyboards is remapped by
   // default to Search until the user changes it from the keyboard settings.
   registry->RegisterIntegerPref(
       prefs::kLanguageRemapExternalMetaKeyTo,
       static_cast<int>(ui::chromeos::ModifierKey::kSearchKey),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   // The following pref isn't synced since the user may desire a different value
   // depending on whether an external keyboard is attached to a particular
   // device.
@@ -303,15 +299,15 @@ void Preferences::RegisterProfilePrefs(
   registry->RegisterBooleanPref(
       prefs::kLanguageXkbAutoRepeatEnabled,
       language_prefs::kXkbAutoRepeatEnabled,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kLanguageXkbAutoRepeatDelay,
       language_prefs::kXkbAutoRepeatDelayInMs,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterIntegerPref(
       prefs::kLanguageXkbAutoRepeatInterval,
       language_prefs::kXkbAutoRepeatIntervalInMs,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 
   // Don't sync the note-taking app; it may not be installed on other devices.
   registry->RegisterStringPref(prefs::kNoteTakingAppId, std::string());
@@ -327,15 +323,14 @@ void Preferences::RegisterProfilePrefs(
 
   // Number of times Data Saver prompt has been shown on 3G data network.
   registry->RegisterIntegerPref(
-      prefs::kDataSaverPromptsShown,
-      0,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      prefs::kDataSaverPromptsShown, 0,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 
   // Initially all existing users would see "What's new" for current version
   // after update.
-  registry->RegisterStringPref(prefs::kChromeOSReleaseNotesVersion,
-                               "0.0.0.0",
-                               user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterStringPref(
+      prefs::kChromeOSReleaseNotesVersion, "0.0.0.0",
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 
   registry->RegisterBooleanPref(prefs::kExternalStorageDisabled, false);
 
@@ -359,17 +354,17 @@ void Preferences::RegisterProfilePrefs(
 
   registry->RegisterBooleanPref(
       prefs::kResolveTimezoneByGeolocation, true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 
   registry->RegisterBooleanPref(
       prefs::kResolveTimezoneByGeolocationMigratedToMethod, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 
   registry->RegisterIntegerPref(
       prefs::kResolveTimezoneByGeolocationMethod,
       static_cast<int>(
           system::TimeZoneResolverManager::TimeZoneResolveMethod::IP_ONLY),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 
   registry->RegisterBooleanPref(prefs::kCaptivePortalAuthenticationIgnoresProxy,
                                 true);
@@ -406,16 +401,16 @@ void Preferences::RegisterProfilePrefs(
   // Text-to-speech prefs.
   registry->RegisterDictionaryPref(
       prefs::kTextToSpeechLangToVoiceName,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
-  registry->RegisterDoublePref(prefs::kTextToSpeechRate,
-                               blink::mojom::kSpeechSynthesisDefaultRate,
-                               user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
-  registry->RegisterDoublePref(prefs::kTextToSpeechPitch,
-                               blink::mojom::kSpeechSynthesisDefaultPitch,
-                               user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
-  registry->RegisterDoublePref(prefs::kTextToSpeechVolume,
-                               blink::mojom::kSpeechSynthesisDefaultVolume,
-                               user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
+  registry->RegisterDoublePref(
+      prefs::kTextToSpeechRate, blink::mojom::kSpeechSynthesisDefaultRate,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
+  registry->RegisterDoublePref(
+      prefs::kTextToSpeechPitch, blink::mojom::kSpeechSynthesisDefaultPitch,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
+  registry->RegisterDoublePref(
+      prefs::kTextToSpeechVolume, blink::mojom::kSpeechSynthesisDefaultVolume,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 
   // By default showing Sync Consent is set to true. It can changed by policy.
   registry->RegisterBooleanPref(prefs::kEnableSyncConsent, true);

chrome/browser/chromeos/printing/cups_printers_manager.cc

@@ -593,7 +593,7 @@ void CupsPrintersManager::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(
       prefs::kUserNativePrintersAllowed, true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterBooleanPref(prefs::kPrintingSendUsernameAndFilenameEnabled,
                                 false);
   PrintServersProvider::RegisterProfilePrefs(registry);

chrome/browser/profiles/profile.cc

@@ -201,7 +201,7 @@ void Profile::RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
   // in user's profile for other platforms as well.
   registry->RegisterStringPref(
       language::prefs::kApplicationLocale, std::string(),
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF);
   registry->RegisterStringPref(prefs::kApplicationLocaleBackup, std::string());
   registry->RegisterStringPref(prefs::kApplicationLocaleAccepted,
                                std::string());

chrome/browser/profiles/profile_impl.cc

@@ -451,7 +451,7 @@ void ProfileImpl::RegisterProfilePrefs(
 #if defined(OS_CHROMEOS)
   registry->RegisterBooleanPref(
       prefs::kOobeMarketingOptInScreenFinished, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 #endif  // defined(OS_CHROMEOS)
 #if !defined(OS_ANDROID)
   registry->RegisterBooleanPref(prefs::kShowCastIconInToolbar, false);

chromeos/components/proximity_auth/proximity_auth_profile_pref_manager.cc

@@ -47,7 +47,7 @@ void ProximityAuthProfilePrefManager::RegisterPrefs(
   registry->RegisterDictionaryPref(prefs::kProximityAuthRemoteBleDevices);
   registry->RegisterBooleanPref(
       prefs::kProximityAuthIsChromeOSLoginEnabled, false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 }
 
 void ProximityAuthProfilePrefManager::StartSyncingToLocalState(

chromeos/components/tether/tether_host_response_recorder.cc

@@ -23,10 +23,10 @@ void TetherHostResponseRecorder::RegisterPrefs(
   // same prioritization criteria.
   registry->RegisterListPref(
       prefs::kMostRecentTetherAvailablilityResponderIds,
-      user_prefs::PrefRegistrySyncable::PrefRegistrationFlags::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
   registry->RegisterListPref(
       prefs::kMostRecentConnectTetheringResponderIds,
-      user_prefs::PrefRegistrySyncable::PrefRegistrationFlags::SYNCABLE_PREF);
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 }
 
 TetherHostResponseRecorder::TetherHostResponseRecorder(

components/language/core/browser/language_prefs.cc

@@ -37,8 +37,9 @@ void LanguagePrefs::RegisterProfilePrefs(
   registry->RegisterStringPref(language::prefs::kPreferredLanguages,
                                kFallbackInputMethodLocale);
 
-  registry->RegisterStringPref(language::prefs::kPreferredLanguagesSyncable, "",
-                               user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterStringPref(
+      language::prefs::kPreferredLanguagesSyncable, "",
+      user_prefs::PrefRegistrySyncable::SYNCABLE_OS_PREF);
 #endif
   registry->RegisterListPref(language::prefs::kFluentLanguages,
                              LanguagePrefs::GetDefaultFluentLanguages(),

components/pref_registry/pref_registry_syncable.cc

@@ -10,12 +10,21 @@
 #include "components/prefs/default_pref_store.h"
 
 namespace user_prefs {
+namespace {
 
-PrefRegistrySyncable::PrefRegistrySyncable() {
-}
+constexpr uint32_t kSyncablePrefFlags =
+#if defined(OS_CHROMEOS)
+    PrefRegistrySyncable::SYNCABLE_OS_PREF |
+    PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF |
+#endif
+    PrefRegistrySyncable::SYNCABLE_PREF |
+    PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF;
 
-PrefRegistrySyncable::~PrefRegistrySyncable() {
-}
+}  // namespace
+
+PrefRegistrySyncable::PrefRegistrySyncable() = default;
+
+PrefRegistrySyncable::~PrefRegistrySyncable() = default;
 
 void PrefRegistrySyncable::SetSyncableRegistrationCallback(
     const SyncableRegistrationCallback& cb) {
@@ -28,9 +37,13 @@ void PrefRegistrySyncable::OnPrefRegistered(const std::string& path,
   // SYNCABLE_PRIORITY_PREF flags at the same time.
   DCHECK(!(flags & PrefRegistrySyncable::SYNCABLE_PREF) ||
          !(flags & PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF));
+#if defined(OS_CHROMEOS)
+  // Ditto for the mutually exclusive OS pref flags.
+  DCHECK(!(flags & PrefRegistrySyncable::SYNCABLE_OS_PREF) ||
+         !(flags & PrefRegistrySyncable::SYNCABLE_OS_PRIORITY_PREF));
+#endif
 
-  if (flags & PrefRegistrySyncable::SYNCABLE_PREF ||
-      flags & PrefRegistrySyncable::SYNCABLE_PRIORITY_PREF) {
+  if (flags & kSyncablePrefFlags) {
     if (!callback_.is_null())
       callback_.Run(path, flags);
   }