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

chrome/browser/ui/cocoa/bookmarks/bookmark_all_tabs_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 36 matching lines @@
     model->AddURL(folder_a_, 1, ASCIIToUTF16("a-1"), GURL("http://a-1.com"));
     model->AddURL(folder_a_, 2, ASCIIToUTF16("a-2"), GURL("http://a-2.com"));
   }
 
   virtual BookmarkAllTabsControllerOverride* CreateController() {
     return [[BookmarkAllTabsControllerOverride alloc]
             initWithParentWindow:test_window()
                          profile:profile()
                           parent:folder_a_
                              url:GURL()
-                           title:string16()
+                           title:base::string16()
                    configuration:BookmarkEditor::SHOW_TREE];
   }
 
   virtual void SetUp() {
     CocoaProfileTest::SetUp();
     ASSERT_TRUE(profile());
 
     CreateModel();
     controller_ = CreateController();
     [controller_ runAsModalSheet];
   }
 
   virtual void TearDown() {
     controller_ = NULL;
     CocoaProfileTest::TearDown();
   }
 };
 
 TEST_F(BookmarkAllTabsControllerTest, BookmarkAllTabs) {
   // OK button should always be enabled.
   EXPECT_TRUE([controller_ okButtonEnabled]);
   [controller_ selectTestNodeInBrowser:folder_a_];
   [controller_ setDisplayName:@"ALL MY TABS"];
   [controller_ ok:nil];
   EXPECT_EQ(4, folder_a_->child_count());
   const BookmarkNode* folderChild = folder_a_->GetChild(3);
   EXPECT_EQ(folderChild->GetTitle(), ASCIIToUTF16("ALL MY TABS"));
   EXPECT_EQ(3, folderChild->child_count());
 }