[Payments] Implement payment instrument icons

content/browser/payments/payment_instrument_icon_fetcher.cc

+// 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 "content/browser/payments/payment_instrument_icon_fetcher.h"
+
+#include "base/base64.h"
+#include "base/bind_helpers.h"
+#include "content/browser/storage_partition_impl.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/common/service_manager_connection.h"
+#include "net/base/load_flags.h"
+#include "net/http/http_status_code.h"
+#include "net/traffic_annotation/network_traffic_annotation.h"
+#include "services/data_decoder/public/cpp/decode_image.h"
+#include "services/service_manager/public/cpp/connector.h"
+#include "ui/gfx/geometry/size.h"
+#include "ui/gfx/image/image.h"
+
+namespace content {
+
+namespace {
+
+net::NetworkTrafficAnnotationTag g_traffic_annotation =

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

Does this cause an exit time destructor? No reason to keep it in the anonymous
namespace, since it's used only once. Please put it inside the function where
it's being used.

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

It may be used multiple times when there are multiple image objects for a
instrument. That's the main reason I want to keep it.
net::NetworkTrafficAnnotationTag in essence is a struct has an unsigned integer
as its member. 

+    net::DefineNetworkTrafficAnnotation("payment_instrument_icon_fetcher", R"(
+        semantics {
+          sender: "Web Payments"
+          description:
+            "Chromium downloads payment instrument icons when registering
+             payment instruments."
+          trigger:
+            "When user navigates to a website to register web payment apps."
+          data:
+            "URL of the required icon to fetch. No user information is sent."
+          destination: WEBSITE
+        }
+        policy {
+          cookies_allowed: false
+          setting:
+            "This feature cannot be disabled in settings. Users can refuse
+             to install web payment apps."
+          policy_exception_justification: "Not implemented."
+        })");
+
+}  // namespace
+
+void PaymentInstrumentIconFetcher::start(
+    const GURL& scope,
+    const std::vector<payments::mojom::ImageObjectPtr>& image_objects,
+    scoped_refptr<ServiceWorkerContextWrapper> service_worker_context,
+    PaymentInstrumentIconFetcherCallback callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  scope_ = scope;
+  DCHECK(scope_.is_valid());
+
+  for (const auto& obj : image_objects) {
+    payments::mojom::ImageObjectPtr image_object =
+        payments::mojom::ImageObject::New();
+    image_object->src = obj->src;
+    image_object->sizes = obj->sizes;
+    image_object->type = obj->type;
+    image_objects_.emplace_back(std::move(image_object));
+  }
+  DCHECK_GT(image_objects_.size(), 0U);
+
+  callback_ = std::move(callback);
+
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&PaymentInstrumentIconFetcher::StartFromUIThread,
+                 base::Unretained(this), service_worker_context));
+}
+
+void PaymentInstrumentIconFetcher::StartFromUIThread(
+    scoped_refptr<ServiceWorkerContextWrapper> service_worker_context) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  url_request_context_getter_ = scoped_refptr<net::URLRequestContextGetter>(
+      service_worker_context->storage_partition()->GetURLRequestContext());
+  if (url_request_context_getter_.get() == nullptr) {
+    PostCallbackToIOThread("");
+    return;
+  }
+
+  checking_image_object_index_ = 0;
+  FetchIcon();
+}
+
+void PaymentInstrumentIconFetcher::FetchIcon() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  if (checking_image_object_index_ >= image_objects_.size()) {
+    PostCallbackToIOThread("");
+    return;
+  }
+
+  GURL icon_src_url(image_objects_[checking_image_object_index_]->src);
+  if (!icon_src_url.is_valid()) {
+    icon_src_url =
+        scope_.Resolve(image_objects_[checking_image_object_index_]->src);
+  }
+
+  if (!icon_src_url.is_valid()) {
+    checking_image_object_index_++;
+    FetchIcon();
+    return;
+  }
+
+  fetcher_ = net::URLFetcher::Create(icon_src_url, net::URLFetcher::GET, this,
+                                     g_traffic_annotation);
+  fetcher_->SetRequestContext(url_request_context_getter_.get());
+  fetcher_->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
+                         net::LOAD_DO_NOT_SAVE_COOKIES);
+  fetcher_->SetStopOnRedirect(true);
+  fetcher_->Start();
+}
+
+void PaymentInstrumentIconFetcher::OnURLFetchComplete(
+    const net::URLFetcher* source) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  DCHECK_EQ(fetcher_.get(), source);
+  std::unique_ptr<net::URLFetcher> free_fetcher = std::move(fetcher_);
+
+  std::string data;
+  if (!(source->GetStatus().is_success() &&
+        source->GetResponseCode() == net::HTTP_OK &&
+        source->GetResponseAsString(&data))) {
+    checking_image_object_index_++;
+    FetchIcon();
+    return;
+  }
+
+  service_manager::mojom::ConnectorRequest connector_request;
+  std::unique_ptr<service_manager::Connector> connector =
+      service_manager::Connector::Create(&connector_request);
+  content::ServiceManagerConnection::GetForProcess()
+      ->GetConnector()
+      ->BindConnectorRequest(std::move(connector_request));
+
+  std::vector<uint8_t> image_data(data.begin(), data.end());
+  data_decoder::DecodeImage(
+      connector.get(), image_data, data_decoder::mojom::ImageCodec::DEFAULT,
+      false, data_decoder::kDefaultMaxSizeInBytes, gfx::Size(),
+      base::Bind(&PaymentInstrumentIconFetcher::DecodeImageCallback,
+                 base::Unretained(this)));
+}
+
+void PaymentInstrumentIconFetcher::DecodeImageCallback(const SkBitmap& bitmap) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  if (bitmap.isNull() || bitmap.empty()) {
+    checking_image_object_index_++;
+    FetchIcon();
+    return;
+  }
+
+  gfx::Image decoded_image = gfx::Image::CreateFrom1xBitmap(bitmap);
+  scoped_refptr<base::RefCountedMemory> raw_data = decoded_image.As1xPNGBytes();
+  std::string base_64;
+  base::Base64Encode(
+      base::StringPiece(raw_data->front_as<char>(), raw_data->size()),
+      &base_64);
+
+  PostCallbackToIOThread(base_64);
+}
+
+void PaymentInstrumentIconFetcher::PostCallbackToIOThread(
+    const std::string& decoded_data) {
+  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
+                          base::BindOnce(std::move(callback_), decoded_data));
+}
+
+}  // namespace content