[Payments] Implement payment instrument icons

content/browser/payments/payment_instrument_icon_fetcher.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 CONTENT_BROWSER_PAYMENTS_PAYMENT_INSTRUMENT_ICON_FETCHER_H_
+#define CONTENT_BROWSER_PAYMENTS_PAYMENT_INSTRUMENT_ICON_FETCHER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "components/payments/mojom/payment_app.mojom.h"
+#include "content/browser/service_worker/service_worker_context_wrapper.h"
+#include "net/url_request/url_fetcher.h"
+#include "net/url_request/url_fetcher_delegate.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+
+namespace content {
+
+class PaymentInstrumentIconFetcher : private net::URLFetcherDelegate {
+ public:
+  using PaymentInstrumentIconFetcherCallback =
+      base::OnceCallback<void(const std::string&)>;
+
+  PaymentInstrumentIconFetcher() {}
+  ~PaymentInstrumentIconFetcher() override {}

[please use gerrit instead, 2017/06/08 21:34:11]

Don't inline destructors for classes with complex member variables.

[gogerald1, 2017/06/09 14:23:24]

Done.

+
+  // Starts fetching and decoding payment instrument icon from online. The
+  // result will be send back through |callback|.
+  // TODO(gogerald): Right now, we return the first fetchable and decodable icon
+  // with smallest available size. We may add more logic to choose appropriate
+  // icon according to icon size and our usage.
+  void start(const GURL& scope,
+             const std::vector<payments::mojom::ImageObjectPtr>& image_objects,
+             scoped_refptr<ServiceWorkerContextWrapper> service_worker_context,
+             PaymentInstrumentIconFetcherCallback callback);
+
+ private:
+  void StartFromUIThread(
+      scoped_refptr<ServiceWorkerContextWrapper> service_worker_context);
+  void PostCallbackToIOThread(const std::string& decoded_data);
+
+  // data_decoder::mojom::ImageDecoder::DecodeImageCallback.
+  void DecodeImageCallback(const SkBitmap& bitmap);
+
+  // Override net::URLFetcherDelegate.
+  void OnURLFetchComplete(const net::URLFetcher* source) override;
+
+  void FetchIcon();
+
+  // Scope of the service worker of the payment instrument belongs to.
+  GURL scope_;
+
+  // Declared set of image objects of the payment instrument.
+  std::vector<payments::mojom::ImageObjectPtr> image_objects_;
+
+  // The index of the currently checking image object in image_objects_.
+  size_t checking_image_object_index_;

[please use gerrit instead, 2017/06/08 21:34:11]

Need to initialize in the constructor, otherwise it's a random value, which
leads to all kinds of bugs.

[gogerald1, 2017/06/09 14:23:24]

It was initialized in start() public interface,

+
+  // The callback to notify after complete.
+  PaymentInstrumentIconFetcherCallback callback_;
+
+  // The url request context getter for fetching icon from online.
+  scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;
+
+  // The url fetcher to fetch raw icon from online.
+  std::unique_ptr<net::URLFetcher> fetcher_;
+
+  DISALLOW_COPY_AND_ASSIGN(PaymentInstrumentIconFetcher);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_PAYMENTS_PAYMENT_INSTRUMENT_ICON_FETCHER_H_