Update some uses of UTF conversions in chrome/browser to use the base:: namespace.

chrome/browser/tab_contents/spelling_menu_observer.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/tab_contents/spelling_menu_observer.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/i18n/case_conversion.h"
 #include "base/prefs/pref_service.h"
@@ skipping 270 matching lines @@
 
   if (command_id == IDC_CONTENT_CONTEXT_SPELLING_SUGGESTION ||
       command_id == IDC_SPELLCHECK_ADD_TO_DICTIONARY) {
     // GetHostForProfile() can return null when the suggested word is provided
     // by Web SpellCheck API.
     Profile* profile = proxy_->GetProfile();
     if (profile) {
       SpellcheckService* spellcheck =
           SpellcheckServiceFactory::GetForContext(profile);
       if (spellcheck) {
-        spellcheck->GetCustomDictionary()->AddWord(UTF16ToUTF8(
+        spellcheck->GetCustomDictionary()->AddWord(base::UTF16ToUTF8(
             misspelled_word_));
         spellcheck->GetFeedbackSender()->AddedToDictionary(misspelling_hash_);
       }
     }
 #if defined(OS_MACOSX)
     spellcheck_mac::AddWord(misspelled_word_);
 #endif
   }
 
   // The spelling service can be toggled by the user only if it is not managed.
@@ skipping 109 matching lines @@
   // Append '.' characters to the end of "Checking".
   loading_frame_ = (loading_frame_ + 1) & 3;
   base::string16 loading_message =
       loading_message_ + base::string16(loading_frame_,'.');
 
   // Update the menu item with the text. We disable this item to prevent users
   // from selecting it.
   proxy_->UpdateMenuItem(IDC_CONTENT_CONTEXT_SPELLING_SUGGESTION, false, false,
                          loading_message);
 }