Use a direct include of strings headers in chrome_frame/.

chrome_frame/policy_settings.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_frame/policy_settings.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/registry.h"
 #include "chrome_frame/utils.h"
 #include "policy/policy_constants.h"
 
 namespace {
 
 // This array specifies the order in which registry keys are tested.  Do not
 // change this unless the decision is made product-wide (i.e., in Chrome's
 // configuration policy provider).
@@ skipping 143 matching lines @@
   swap(renderer_exclusion_list_, renderer_exclusion_list);
   swap(content_type_list_, content_type_list);
   swap(application_locale_, application_locale);
   swap(additional_launch_parameters_, additional_launch_parameters);
 }
 
 // static
 PolicySettings* PolicySettings::GetInstance() {
   return Singleton<PolicySettings>::get();
 }