Use GN buildflags and features to configure account consistency

components/signin/core/common/signin_switches.cc

 // 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.
 
 #include "components/signin/core/common/signin_switches.h"
 
 namespace switches {
 
 // Clears the token service before using it. This allows simulating the
 // expiration of credentials during testing.
 const char kClearTokenService[] = "clear-token-service";
 
 // Disables sign-in promo.
 const char kDisableSigninPromo[] = "disable-signin-promo";
 
 // Disables sending signin scoped device id to LSO with refresh token request.
 const char kDisableSigninScopedDeviceId[] = "disable-signin-scoped-device-id";
 
-#if !defined(OS_ANDROID) && !defined(OS_IOS)
+#if !BUILDFLAG(ENABLE_MIRROR)
 // Command line flag for enabling account consistency. Default mode is disabled.
 // Mirror is a legacy mode in which Google accounts are always addded to Chrome,
 // and Chrome then adds them to the Google authentication cookies.
 // Dice is a new experiment in which Chrome is aware of the accounts in the
 // Google authentication cookies.
 const char kAccountConsistency[] = "account-consistency";
 
 // Values for the kAccountConsistency flag.
 const char kAccountConsistencyMirror[] = "mirror";
 const char kAccountConsistencyDice[] = "dice";
 #endif
 
 // Enables sending EnableRefreshTokenAnnotationRequest.
 extern const char kEnableRefreshTokenAnnotationRequest[] =
     "enable-refresh-token-annotation-request";
 
 // Enables sign-in promo.
 const char kEnableSigninPromo[] = "enable-signin-promo";
 
 // Enables multiple account versions of chrome.identity APIs.
 const char kExtensionsMultiAccount[] = "extensions-multi-account";
 
 }  // namespace switches