base: Fix the TODO in ListValue::Remove().

chrome/browser/chromeos/user_cros_settings_provider.cc

 // Copyright (c) 2011 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/chromeos/user_cros_settings_provider.h"
 
 #include <map>
 #include <set>
 
 #include "base/hash_tables.h"
@@ skipping 643 matching lines @@
   prefs->ScheduleSavePersistentPrefs();
 }
 
 void UserCrosSettingsProvider::UnwhitelistUser(const std::string& email) {
   SignedSettingsHelper::Get()->StartWhitelistOp(
       email, false, UserCrosSettingsTrust::GetInstance());
 
   PrefService* prefs = g_browser_process->local_state();
   ListPrefUpdate cached_whitelist_update(prefs, kAccountsPrefUsers);
   StringValue email_value(email);
-  if (cached_whitelist_update->Remove(email_value) != -1)
+  if (cached_whitelist_update->Remove(email_value, NULL))
     prefs->ScheduleSavePersistentPrefs();
 }
 
 // static
 void UserCrosSettingsProvider::UpdateCachedOwner(const std::string& email) {
   UpdateCacheString(kDeviceOwner, email, USE_VALUE_SUPPLIED);
 }
 
 }  // namespace chromeos