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

chrome/browser/search_engines/template_url_service.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/search_engines/template_url_service.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/environment.h"
 #include "base/guid.h"
 #include "base/i18n/case_conversion.h"
 #include "base/memory/scoped_vector.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/stl_util.h"
-#include "base/string_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time.h"
 #include "chrome/browser/google/google_url_tracker.h"
 #include "chrome/browser/history/history_notifications.h"
 #include "chrome/browser/history/history_service.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/net/url_fixer_upper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/rlz/rlz.h"
 #include "chrome/browser/search_engines/search_host_to_urls_map.h"
@@ skipping 2494 matching lines @@
     // Don't log anything if the user has a NULL default search provider. A
     // logged value of 0 indicates a custom default search provider.
     if (default_search_provider_) {
       UMA_HISTOGRAM_ENUMERATION(
           kDSPHistogramName,
           default_search_provider_->prepopulate_id(),
           TemplateURLPrepopulateData::kMaxPrepopulatedEngineID);
     }
   }
 }