Use a direct include of strings headers in chrome/auto*/.

chrome/browser/autocomplete/history_url_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/history_url_provider.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/autocomplete/autocomplete_match.h"
 #include "chrome/browser/autocomplete/autocomplete_provider_listener.h"
 #include "chrome/browser/history/history_backend.h"
 #include "chrome/browser/history/history_database.h"
 #include "chrome/browser/history/history_service.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/history/history_types.h"
 #include "chrome/browser/net/url_fixer_upper.h"
 #include "chrome/browser/omnibox/omnibox_field_trial.h"
@@ skipping 1050 matching lines @@
         &match.contents_class);
   }
   match.description = info.title();
   AutocompleteMatch::ClassifyMatchInString(params->input.text(),
                                            info.title(),
                                            ACMatchClassification::NONE,
                                            &match.description_class);
   RecordAdditionalInfoFromUrlRow(info, &match);
   return match;
 }