Use a direct include of strings headers in chrome_frame/.

chrome_frame/metrics_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.
 
 //------------------------------------------------------------------------------
 // Description of the life cycle of a instance of MetricsService.
 //
 //  OVERVIEW
 //
 // A MetricsService instance is created at ChromeFrame startup in
@@ skipping 27 matching lines @@
 //-----------------------------------------------------------------------------
 
 #include "chrome_frame/metrics_service.h"
 
 #include <atlbase.h>
 #include <atlwin.h>
 #include <objbase.h>
 #include <windows.h>
 
 #include "base/metrics/statistics_recorder.h"
-#include "base/string16.h"
-#include "base/string_util.h"
-#include "base/stringprintf.h"
+#include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/synchronization/lock.h"
 #include "base/win/scoped_comptr.h"
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/metrics/metrics_log_base.h"
 #include "chrome/common/metrics/metrics_log_manager.h"
 #include "chrome/installer/util/browser_distribution.h"
 #include "chrome/installer/util/google_update_settings.h"
 #include "chrome_frame/bind_status_callback_impl.h"
 #include "chrome_frame/crash_reporting/crash_metrics.h"
@@ skipping 392 matching lines @@
     version += "-F";
     if (!version_info.IsOfficialBuild())
       version.append("-devel");
     return version;
   } else {
     NOTREACHED() << "Unable to retrieve version string.";
   }
 
   return std::string();
 }