Revert of Move JoinString to the base namespace

chrome/browser/extensions/extension_message_bubble_controller.cc

 // Copyright (c) 2013 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/extensions/extension_message_bubble_controller.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
@@ skipping 123 matching lines @@
     int old_size = extension_list.size();
     extension_list.erase(extension_list.begin() + kMaxExtensionsToShow,
                          extension_list.end());
     extension_list.push_back(delegate_->GetOverflowText(base::IntToString16(
         old_size - kMaxExtensionsToShow)));
   }
   const base::char16 bullet_point = 0x2022;
   base::string16 prefix = bullet_point + base::ASCIIToUTF16(" ");
   for (base::string16& str : extension_list)
     str.insert(0, prefix);
-  return base::JoinString(extension_list, base::ASCIIToUTF16("\n"));
+  return JoinString(extension_list, base::ASCIIToUTF16("\n"));
 }
 
 const ExtensionIdList& ExtensionMessageBubbleController::GetExtensionIdList() {
   return *GetOrCreateExtensionList();
 }
 
 bool ExtensionMessageBubbleController::CloseOnDeactivate() { return false; }
 
 void ExtensionMessageBubbleController::HighlightExtensionsIfNecessary() {
   if (delegate_->ShouldHighlightExtensions() && !did_highlight_) {
@@ skipping 78 matching lines @@
   return &extension_list_;
 }
 
 void ExtensionMessageBubbleController::OnClose() {
   AcknowledgeExtensions();
   if (did_highlight_)
     ExtensionToolbarModel::Get(profile_)->StopHighlighting();
 }
 
 }  // namespace extensions