Revert of Move JoinString to the base namespace

ui/message_center/views/notification_view.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 "ui/message_center/views/notification_view.h"
 
 #include "base/command_line.h"
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 316 matching lines @@
 void NotificationView::SetAccessibleName(const Notification& notification) {
   std::vector<base::string16> accessible_lines;
   accessible_lines.push_back(notification.title());
   accessible_lines.push_back(notification.message());
   accessible_lines.push_back(notification.context_message());
   std::vector<NotificationItem> items = notification.items();
   for (size_t i = 0; i < items.size() && i < kNotificationMaximumItems; ++i) {
     accessible_lines.push_back(items[i].title + base::ASCIIToUTF16(" ") +
                                items[i].message);
   }
-  set_accessible_name(
-      base::JoinString(accessible_lines, base::ASCIIToUTF16("\n")));
+  set_accessible_name(JoinString(accessible_lines, '\n'));
 }
 
 NotificationView::NotificationView(MessageCenterController* controller,
                                    const Notification& notification)
     : MessageView(this,
                   notification.id(),
                   notification.notifier_id(),
                   notification.small_image().AsImageSkia(),
                   notification.display_source()),
       controller_(controller),
@@ skipping 437 matching lines @@
 
   return message_line_limit;
 }
 
 int NotificationView::GetMessageHeight(int width, int limit) const {
   return message_view_ ?
          message_view_->GetSizeForWidthAndLines(width, limit).height() : 0;
 }
 
 }  // namespace message_center