Add base:: namespace to straggling string16s left in chrome/browser/ui.

chrome/browser/ui/cocoa/bookmarks/bookmark_editor_base_controller_unittest.mm

 // 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.
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
@@ skipping 57 matching lines @@
     model->AddURL(root, 3, ASCIIToUTF16("d"), GURL("http://d-0.com"));
   }
 
   virtual BookmarkEditorBaseController* CreateController() {
     return [[BookmarkEditorBaseController alloc]
             initWithParentWindow:test_window()
                          nibName:@"BookmarkAllTabs"
                          profile:profile()
                           parent:folder_b_0_
                              url:GURL()
-                           title:string16()
+                           title:base::string16()
                    configuration:BookmarkEditor::SHOW_TREE];
   }
 
   virtual void SetUp() OVERRIDE {
     CocoaProfileTest::SetUp();
     ASSERT_TRUE(profile());
 
     CreateModel();
     controller_ = CreateController();
     EXPECT_TRUE([controller_ window]);
@@ skipping 176 matching lines @@
       reinterpret_cast<const BookmarkNode*>(&children);
   BookmarkFolderInfo* info =
     [BookmarkFolderInfo bookmarkFolderInfoWithFolderName:@"name"
                                               folderNode:fakeNode
                                                 children:children];
   EXPECT_TRUE(info);
   EXPECT_EQ([info folderName], @"name");
   EXPECT_EQ([info children], children);
   EXPECT_EQ([info folderNode], fakeNode);
 }