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

chrome/test/chromedriver/element_util.cc

 // Copyright (c) 2013 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/chromedriver/element_util.h"
 
-#include "base/string_util.h"
-#include "base/stringprintf.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
 #include "base/threading/platform_thread.h"
 #include "base/time.h"
 #include "base/values.h"
 #include "chrome/test/chromedriver/basic_types.h"
 #include "chrome/test/chromedriver/chrome/js.h"
 #include "chrome/test/chromedriver/chrome/status.h"
 #include "chrome/test/chromedriver/chrome/web_view.h"
 #include "chrome/test/chromedriver/session.h"
 #include "third_party/webdriver/atoms.h"
 
@@ skipping 558 matching lines @@
     status = ScrollElementRegionIntoViewHelper(
         rit->parent_frame_id, web_view, frame_element_id,
         WebRect(region_offset, region_size),
         center, verify_clickable, &region_offset);
     if (status.IsError())
       return status;
   }
   *location = region_offset;
   return Status(kOk);
 }