[Merge M60][Payments] Refactor the year and month combobox models and preselect.

chrome/browser/ui/views/payments/preselected_combobox_model.cc

Index: chrome/browser/ui/views/payments/preselected_combobox_model.cc
diff --git a/chrome/browser/ui/views/payments/preselected_combobox_model.cc b/chrome/browser/ui/views/payments/preselected_combobox_model.cc
deleted file mode 100644
index 14339d980df14f084311a665b8fb409cd738818a..0000000000000000000000000000000000000000
--- a/chrome/browser/ui/views/payments/preselected_combobox_model.cc
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright 2017 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/browser/ui/views/payments/preselected_combobox_model.h"
-
-namespace payments {
-
-PreselectedComboboxModel::PreselectedComboboxModel(
-    const std::vector<base::string16>& items,
-    int default_index)
-    : SimpleComboboxModel(items), default_index_(default_index) {}
-
-PreselectedComboboxModel::~PreselectedComboboxModel() {}
-
-int PreselectedComboboxModel::GetDefaultIndex() const {
-  return default_index_;
-}
-
-}  // namespace payments