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

chrome/test/webdriver/commands/webdriver_command.cc

 // Copyright (c) 2011 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/webdriver/commands/webdriver_command.h"
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
-#include "base/string_util.h"
-#include "base/stringprintf.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "chrome/test/webdriver/commands/response.h"
 #include "chrome/test/webdriver/webdriver_error.h"
 #include "chrome/test/webdriver/webdriver_logging.h"
 #include "chrome/test/webdriver/webdriver_session.h"
 #include "chrome/test/webdriver/webdriver_session_manager.h"
 #include "chrome/test/webdriver/webdriver_util.h"
 
 namespace webdriver {
 
@@ skipping 59 matching lines @@
           "Command finished (%s) with response %s",
           JoinString(path_segments_, '/').c_str(),
           JsonStringifyForDisplay(response->GetDictionary()).c_str()));
 }
 
 bool WebDriverCommand::ShouldRunPreAndPostCommandHandlers() {
   return true;
 }
 
 }  // namespace webdriver