Use a direct include of strings headers, delete some strings forwarding headers.

chrome/browser/ui/webui/options/preferences_browsertest.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/ui/webui/options/preferences_browsertest.h"
 
 #include <iostream>
 #include <sstream>
 
 #include "base/json/json_reader.h"
@@ skipping 15 matching lines @@
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/test/browser_test_utils.h"
 #include "googleurl/src/gurl.h"
 #include "policy/policy_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 #if defined(OS_CHROMEOS)
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "chrome/browser/chromeos/net/proxy_config_handler.h"
 #include "chrome/browser/chromeos/proxy_cros_settings_parser.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/chromeos/settings/cros_settings_names.h"
 #include "chrome/browser/prefs/proxy_config_dictionary.h"
 #include "chromeos/network/network_state.h"
 #include "chromeos/network/network_state_handler.h"
 #endif
 
 using testing::AllOf;
@@ skipping 780 matching lines @@
   SetProxyPref(chromeos::kProxyHttpPort, base::FundamentalValue(1));
   SetProxyPref(chromeos::kProxyHttpsPort, base::FundamentalValue(2));
   SetProxyPref(chromeos::kProxyFtpPort, base::FundamentalValue(3));
   SetProxyPref(chromeos::kProxySocksPort, base::FundamentalValue(4));
 
   VerifyCurrentProxyServer(
       "http=a.com:1;https=4.3.2.1:2;ftp=c.com:3;socks=socks4://d.com:4");
 }
 
 #endif