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

chrome/test/base/chrome_test_launcher.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 "content/public/test/test_launcher.h"
 
 #include <stack>
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/memory/linked_ptr.h"
 #include "base/process_util.h"
 #include "base/run_loop.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "base/test/test_file_util.h"
 #include "chrome/app/chrome_main_delegate.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/test/base/chrome_test_suite.h"
 #include "content/public/app/content_main.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/test/test_utils.h"
 
@@ skipping 136 matching lines @@
 #elif defined(USE_AURA)
   // TODO(win_ash): when running interactive_ui_tests for Win Ash, use above.
   ui_controls::InstallUIControlsAura(aura::test::CreateUIControlsAura(NULL));
 #endif
 
 #endif
 
   ChromeTestLauncherDelegate launcher_delegate;
   return content::LaunchTests(&launcher_delegate, argc, argv);
 }