Use a direct include of strings headers in url/, win8/.

win8/test/metro_registration_helper.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 "win8/test/metro_registration_helper.h"
 
 #include <shlobj.h>
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/process.h"
 #include "base/process_util.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "base/win/scoped_co_mem.h"
 #include "base/win/scoped_comptr.h"
 #include "base/win/scoped_handle.h"
 #include "win8/test/open_with_dialog_controller.h"
 #include "win8/test/test_registrar_constants.h"
 
 namespace {
 
 const int kRegistrationTimeoutSeconds = 30;
 
@@ skipping 93 matching lines @@
   std::vector<base::string16> choices;
   OpenWithDialogController controller;
   HRESULT hr = controller.RunSynchronously(
       NULL, kDefaultBrowserProtocol, win8::test::kDefaultTestExeName, &choices);
   LOG_IF(ERROR, FAILED(hr)) << std::hex << hr;
   DCHECK(IsTestDefaultForProtocol(kDefaultBrowserProtocol));
   return SUCCEEDED(hr);
 }
 
 }  // namespace win8