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

chrome/browser/signin/signin_manager_base.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/signin/signin_manager_base.h"
 
 #include <string>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/memory/ref_counted.h"
 #include "base/prefs/pref_service.h"
-#include "base/string_util.h"
 #include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/signin/about_signin_internals.h"
 #include "chrome/browser/signin/about_signin_internals_factory.h"
 #include "chrome/browser/signin/signin_global_error.h"
 #include "chrome/browser/signin/signin_manager_cookie_helper.h"
 #include "chrome/browser/signin/token_service.h"
 #include "chrome/browser/signin/token_service_factory.h"
 #include "chrome/browser/sync/sync_prefs.h"
 #include "chrome/browser/ui/global_error/global_error_service.h"
 #include "chrome/browser/ui/global_error/global_error_service_factory.h"
@@ skipping 118 matching lines @@
                     NotifySigninValueChanged(field, value));
 }
 
 void SigninManagerBase::NotifyDiagnosticsObservers(
     const TimedSigninStatusField& field,
     const std::string& value) {
   FOR_EACH_OBSERVER(SigninDiagnosticsObserver,
                     signin_diagnostics_observers_,
                     NotifySigninValueChanged(field, value));
 }