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

chrome/browser/autocomplete/zero_suggest_provider.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/autocomplete/zero_suggest_provider.h"
 
 #include "base/callback.h"
 #include "base/i18n/case_conversion.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/metrics/histogram.h"
@@ skipping 240 matching lines @@
     if (result.empty())
       continue;
 
     int relevance = kDefaultZeroSuggestRelevance;
 
     // Apply valid suggested relevance scores; discard invalid lists.
     if (relevances != NULL && !relevances->GetInteger(index, &relevance))
       relevances = NULL;
     if (types && types->GetString(index, &type) && (type == "NAVIGATION")) {
       // Do not blindly trust the URL coming from the server to be valid.
-      GURL url(URLFixerUpper::FixupURL(UTF16ToUTF8(result), std::string()));
+      GURL url(URLFixerUpper::FixupURL(
+          base::UTF16ToUTF8(result), std::string()));
       if (url.is_valid()) {
         if (descriptions != NULL)
           descriptions->GetString(index, &title);
         navigation_results->push_back(SearchProvider::NavigationResult(
             *this, url, title, false, relevance, relevances != NULL));
       }
     } else {
       suggest_results->push_back(SearchProvider::SuggestResult(
           result, AutocompleteMatchType::SEARCH_SUGGEST, result,
           base::string16(), std::string(), std::string(), false, relevance,
@@ skipping 183 matching lines @@
   match.is_history_what_you_typed_match = false;
   match.allowed_to_be_default_match = true;
 
   // The placeholder suggestion for the current URL has high relevance so
   // that it is in the first suggestion slot and inline autocompleted. It
   // gets dropped as soon as the user types something.
   match.relevance = verbatim_relevance_;
 
   return match;
 }