Revert of Move JoinString to the base namespace

chrome/browser/chromeos/login/session/user_session_manager.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 "chrome/browser/chromeos/login/session/user_session_manager.h"
 
 #include <string>
 
 #include "base/base_paths.h"
 #include "base/bind.h"
@@ skipping 138 matching lines @@
     // from the |locale| and the currently active input method.
     manager->GetInputMethodUtil()->GetFirstLoginInputMethodIds(
         locale,
         session_manager->GetDefaultIMEState(profile)->GetCurrentInputMethod(),
         &input_method_ids);
   }
 
   // Save the input methods in the user's preferences.
   StringPrefMember language_preload_engines;
   language_preload_engines.Init(prefs::kLanguagePreloadEngines, prefs);
-  language_preload_engines.SetValue(base::JoinString(input_method_ids, ","));
+  language_preload_engines.SetValue(JoinString(input_method_ids, ','));
   BootTimesRecorder::Get()->AddLoginTimeMarker("IMEStarted", false);
 
   // Second, we'll set kLanguagePreferredLanguages.
   std::vector<std::string> language_codes;
 
   // The current locale should be on the top.
   language_codes.push_back(locale);
 
   // Add input method IDs based on the input methods, as there may be
   // input methods that are unrelated to the current locale. Example: the
   // hardware keyboard layout xkb:us::eng is used for logging in, but the
   // UI language is set to French. In this case, we should set "fr,en"
   // to the preferred languages preference.
   std::vector<std::string> candidates;
   manager->GetInputMethodUtil()->GetLanguageCodesFromInputMethodIds(
       input_method_ids, &candidates);
   for (size_t i = 0; i < candidates.size(); ++i) {
     const std::string& candidate = candidates[i];
     // Skip if it's already in language_codes.
     if (std::count(language_codes.begin(), language_codes.end(),
                    candidate) == 0) {
       language_codes.push_back(candidate);
     }
   }
 
   // Save the preferred languages in the user's preferences.
   prefs->SetString(prefs::kLanguagePreferredLanguages,
-                   base::JoinString(language_codes, ","));
+                   JoinString(language_codes, ','));
 
   // Indicate that we need to merge the syncable input methods when we sync,
   // since we have not applied the synced prefs before.
   prefs->SetBoolean(prefs::kLanguageShouldMergeInputMethods, true);
 }
 
 #if defined(ENABLE_RLZ)
 // Flag file that disables RLZ tracking, when present.
 const base::FilePath::CharType kRLZDisabledFlagName[] =
     FILE_PATH_LITERAL(".rlz_disabled");
@@ skipping 1525 matching lines @@
   token_handle_util_.reset();
 }
 
 void UserSessionManager::CreateTokenUtilIfMissing() {
   if (!token_handle_util_.get())
     token_handle_util_.reset(
         new TokenHandleUtil(user_manager::UserManager::Get()));
 }
 
 }  // namespace chromeos