[Payment Request] Region data loader

ios/chrome/browser/ui/payments/region_data_loader.h

+// 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.
+
+#ifndef IOS_CHROME_BROWSER_UI_PAYMENTS_REGION_DATA_LOADER_H_
+#define IOS_CHROME_BROWSER_UI_PAYMENTS_REGION_DATA_LOADER_H_
+
+#import <Foundation/Foundation.h>
+
+#include <memory>
+
+#include "base/macros.h"
+#include "ui/base/models/combobox_model_observer.h"
+
+namespace autofill {
+class RegionComboboxModel;
+class RegionDataLoader;
+}  // namespace autofill
+
+namespace ui {
+class ComboboxModel;
+}  // namespace ui
+
+@protocol RegionDataLoaderConsumer
+
+- (void)regionDataLoaderDidSucceedWithRegions:(NSArray<NSString*>*)regions;
+
+@end
+
+class RegionDataLoader : public ui::ComboboxModelObserver {
+ public:
+  RegionDataLoader(id<RegionDataLoaderConsumer> consumer);

[please use gerrit instead, 2017/05/22 14:04:20]

explicit

[Moe, 2017/05/22 15:57:53]

Done.

+  ~RegionDataLoader() override;
+
+  void LoadRegionData(const std::string& country_code,
+                      autofill::RegionDataLoader* autofill_region_data_loader);
+
+  // ui::ComboboxModelObserver
+  void OnComboboxModelChanged(ui::ComboboxModel* model) override;
+
+ private:
+  __weak id<RegionDataLoaderConsumer> consumer_;
+  std::unique_ptr<autofill::RegionComboboxModel> region_model_;

[please use gerrit instead, 2017/05/22 14:04:19]

It appears that you instantiate region_model_ in the constructor and never reset
it. In this case, the best way to keep this variable around is as a member
variable with std::unique<>:

  autofill::RegionComboboxModel region_model_;

You will need to #include the header where this class is declared.

[Moe, 2017/05/22 15:57:53]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(RegionDataLoader);
+};
+
+#endif  // IOS_CHROME_BROWSER_UI_PAYMENTS_REGION_DATA_LOADER_H_