Upstream PO2TS_IOS unit test.

components/signin/ios/browser/profile_oauth2_token_service_ios.mm

 // 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/ios/browser/profile_oauth2_token_service_ios.h"
 
 #include <Foundation/Foundation.h>
 
 #include <set>
 #include <string>
@@ skipping 435 matching lines @@
   }
   accounts_[account_id]->SetLastAuthError(error);
 }
 
 // Clear the authentication error state and notify all observers that a new
 // refresh token is available so that they request new access tokens.
 void ProfileOAuth2TokenServiceIOS::AddOrUpdateAccount(
     const std::string& account_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!account_id.empty());
+  DCHECK(!use_legacy_token_service_);
 
   bool account_present = accounts_.count(account_id) > 0;
   if (account_present && accounts_[account_id]->GetAuthStatus().state() ==
                              GoogleServiceAuthError::NONE) {
     // No need to update the account if it is already a known account and if
     // there is no auth error.
     return;
   }
 
   if (account_present) {
     CancelRequestsForAccount(account_id);
     ClearCacheForAccount(account_id);
   } else {
     accounts_[account_id].reset(new AccountInfo(this, account_id));
   }
   UpdateAuthError(account_id, GoogleServiceAuthError::AuthErrorNone());
   FireRefreshTokenAvailable(account_id);
 }
 
 void ProfileOAuth2TokenServiceIOS::RemoveAccount(
     const std::string& account_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!account_id.empty());
+  DCHECK(!use_legacy_token_service_);
 
   if (accounts_.count(account_id) > 0) {
     CancelRequestsForAccount(account_id);
     ClearCacheForAccount(account_id);
     accounts_.erase(account_id);
     FireRefreshTokenRevoked(account_id);
   }
 }
 
 void ProfileOAuth2TokenServiceIOS::StartUsingSharedAuthentication() {
   if (!use_legacy_token_service_)
     return;
   MutableProfileOAuth2TokenService::RevokeAllCredentials();
   use_legacy_token_service_ = false;
 }
 
 void ProfileOAuth2TokenServiceIOS::SetUseLegacyTokenServiceForTesting(
     bool use_legacy_token_service) {
   use_legacy_token_service_ = use_legacy_token_service;
 }