Use a direct include of strings headers in chrome/browser/r*-s*/.

chrome/browser/spellchecker/spelling_service_client.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/spellchecker/spelling_service_client.h"
 
 #include "base/command_line.h"
 #include "base/json/json_reader.h"
 #include "base/json/string_escape.h"
 #include "base/logging.h"
 #include "base/prefs/pref_service.h"
 #include "base/stl_util.h"
-#include "base/string_util.h"
-#include "base/stringprintf.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/spellcheck_common.h"
 #include "chrome/common/spellcheck_result.h"
 #include "google_apis/google_api_keys.h"
 #include "net/base/load_flags.h"
 #include "net/url_request/url_fetcher.h"
@@ skipping 222 matching lines @@
     fetcher->GetResponseAsString(&data);
     success = ParseResponse(data, &results);
   }
   callback_data->callback.Run(success, callback_data->text, results);
   spellcheck_fetchers_.erase(fetcher.get());
 }
 
 net::URLFetcher* SpellingServiceClient::CreateURLFetcher(const GURL& url) {
   return net::URLFetcher::Create(url, net::URLFetcher::POST, this);
 }