Revert of Move JoinString to the base namespace

chrome/browser/chromeos/preferences.cc

 // Copyright (c) 2012 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/preferences.h"
 
 #include <vector>
 
 #include "ash/autoclick/autoclick_controller.h"
 #include "ash/shell.h"
@@ skipping 609 matching lines @@
                                                    const char* name,
                                                    const std::string& value) {
   VLOG(1) << "Setting " << name << " to '" << value << "'";
 
   std::vector<std::string> split_values;
   if (!value.empty())
     base::SplitString(value, ',', &split_values);
 
   // Transfers the xkb id to extension-xkb id.
   if (input_method_manager_->MigrateInputMethods(&split_values))
-    preload_engines_.SetValue(base::JoinString(split_values, ","));
+    preload_engines_.SetValue(JoinString(split_values, ','));
 
   if (section == std::string(language_prefs::kGeneralSectionName) &&
       name == std::string(language_prefs::kPreloadEnginesConfigName)) {
     ime_state_->ReplaceEnabledInputMethods(split_values);
     return;
   }
 }
 
 void Preferences::SetInputMethodList() {
   // When |preload_engines_| are set, InputMethodManager::ChangeInputMethod()
@@ skipping 41 matching lines @@
   touch_hud_projection_enabled_.SetValue(enabled);
 }
 
 void Preferences::ActiveUserChanged(const user_manager::User* active_user) {
   if (active_user != user_)
     return;
   ApplyPreferences(REASON_ACTIVE_USER_CHANGED, "");
 }
 
 }  // namespace chromeos