Use a direct include of strings headers in chrome/test/.

chrome/test/base/testing_browser_process.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/test/base/testing_browser_process.h"
 
 #include "base/prefs/pref_service.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/bookmarks/bookmark_prompt_controller.h"
 #include "chrome/test/base/testing_browser_process_platform_part.h"
 #include "content/public/browser/notification_service.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/message_center/message_center.h"
 
@@ skipping 360 matching lines @@
 #endif
 }
 
 void TestingBrowserProcess::SetSafeBrowsingService(
     SafeBrowsingService* sb_service) {
 #if !defined(OS_IOS)
   NOTIMPLEMENTED();
   sb_service_ = sb_service;
 #endif
 }