Reland "Add HashAffiliationFetcher skeleton to retrieve affiliations by hash prefix."

This is a reland of 6a5d7abc

Original change's description:
> Add HashAffiliationFetcher skeleton to retrieve affiliations by hash prefix.
>
> This change creates HashAffiliationFetcher skeleton that extends AffiliationFetcherBase.
> This fetcher will provide additional privacy layer as it will request affiliations for a larger group of facets by passing only the prefixes of hashed URLs.
>
> Bug: 1108279
> Change-Id: I4a2b09aa7d8c3c51f4b30ba966a17ba5afb9b09b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2423883
> Commit-Queue: Nela Kaczmarek <nelakaczmarek@google.com>
> Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#812653}

Bug: 1108279
Change-Id: I21fd2060285e117bcba21d6ea48f3a8ae7048de9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2445172
Commit-Queue: Jan Wilken Dörrie <jdoerrie@chromium.org>
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813187}

components/password_manager/core/browser/BUILD.gn

@@ -213,6 +213,8 @@ static_library("browser") {
     "site_affiliation/affiliation_service_impl.h",
     "site_affiliation/asset_link_data.cc",
     "site_affiliation/asset_link_data.h",
+    "site_affiliation/hash_affiliation_fetcher.cc",
+    "site_affiliation/hash_affiliation_fetcher.h",
     "sql_table_builder.cc",
     "sql_table_builder.h",
     "statistics_table.cc",
@@ -651,6 +653,7 @@ source_set("unit_tests") {
     "psl_matching_helper_unittest.cc",
     "site_affiliation/affiliation_service_impl_unittest.cc",
     "site_affiliation/asset_link_data_unittest.cc",
+    "site_affiliation/hash_affiliation_fetcher_unittest.cc",
     "sql_table_builder_unittest.cc",
     "statistics_table_unittest.cc",
     "store_metrics_reporter_unittest.cc",

components/password_manager/core/browser/site_affiliation/hash_affiliation_fetcher.cc

+// Copyright 2020 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 "components/password_manager/core/browser/site_affiliation/hash_affiliation_fetcher.h"
+
+#include <memory>
+
+#include "components/password_manager/core/browser/android_affiliation/affiliation_utils.h"
+#include "google_apis/google_api_keys.h"
+#include "net/base/url_util.h"
+#include "services/network/public/cpp/shared_url_loader_factory.h"
+#include "url/gurl.h"
+
+namespace password_manager {
+
+HashAffiliationFetcher::HashAffiliationFetcher(
+    scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
+    AffiliationFetcherDelegate* delegate)
+    : AffiliationFetcherBase(std::move(url_loader_factory), delegate) {}
+
+HashAffiliationFetcher::~HashAffiliationFetcher() = default;
+
+// TODO: Add an implementation.
+void HashAffiliationFetcher::StartRequest(
+    const std::vector<FacetURI>& facet_uris,
+    RequestInfo request_info) {}
+
+const std::vector<FacetURI>& HashAffiliationFetcher::GetRequestedFacetURIs()
+    const {
+  return requested_facet_uris_;
+}
+// static
+GURL HashAffiliationFetcher::BuildQueryURL() {
+  return net::AppendQueryParameter(
+      GURL("https://www.googleapis.com/affiliation/v1/"
+           "affiliation:lookupByHashPrefix"),
+      "key", google_apis::GetAPIKey());
+}
+
+}  // namespace password_manager

components/password_manager/core/browser/site_affiliation/hash_affiliation_fetcher.h

+// Copyright 2020 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 COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_SITE_AFFILIATION_HASH_AFFILIATION_FETCHER_H_
+#define COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_SITE_AFFILIATION_HASH_AFFILIATION_FETCHER_H_
+
+#include "components/password_manager/core/browser/site_affiliation/affiliation_fetcher_base.h"
+
+namespace password_manager {
+
+// Fetches authoritative information about facets' affiliations with additional
+// privacy layer. It uses SHA-256 to hash facet URLs and sends only a specified
+// amount of hash prefixes to eventually retrieve a larger group of affiliations
+// including those actually required.
+class HashAffiliationFetcher : public AffiliationFetcherBase {
+ public:
+  HashAffiliationFetcher(
+      scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
+      AffiliationFetcherDelegate* delegate);
+  ~HashAffiliationFetcher() override;
+
+  void StartRequest(const std::vector<FacetURI>& facet_uris,
+                    RequestInfo request_info) override;
+
+  // AffiliationFetcherInterface
+  const std::vector<FacetURI>& GetRequestedFacetURIs() const override;
+
+  // Builds the URL for the Affiliation API's lookup method.
+  static GURL BuildQueryURL();
+
+ private:
+  std::vector<FacetURI> requested_facet_uris_;
+};
+
+}  // namespace password_manager
+
+#endif  // COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_SITE_AFFILIATION_HASH_AFFILIATION_FETCHER_H_

components/password_manager/core/browser/site_affiliation/hash_affiliation_fetcher_unittest.cc

+// Copyright 2020 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 "components/password_manager/core/browser/site_affiliation/hash_affiliation_fetcher.h"
+
+#include "components/password_manager/core/browser/android_affiliation/mock_affiliation_fetcher_delegate.h"
+#include "net/base/url_util.h"
+#include "services/network/public/cpp/weak_wrapper_shared_url_loader_factory.h"
+#include "services/network/test/test_url_loader_factory.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "url/gurl.h"
+
+namespace password_manager {
+
+class HashAffiliationFetcherTest : public testing::Test {
+ public:
+  HashAffiliationFetcherTest() = default;
+  ~HashAffiliationFetcherTest() override = default;
+};
+
+TEST_F(HashAffiliationFetcherTest, BuildQueryURL) {
+  network::TestURLLoaderFactory test_url_loader_factory;
+  scoped_refptr<network::SharedURLLoaderFactory> test_shared_loader_factory =
+      base::MakeRefCounted<network::WeakWrapperSharedURLLoaderFactory>(
+          &test_url_loader_factory);
+  MockAffiliationFetcherDelegate mock_delegate;
+
+  HashAffiliationFetcher fetcher(test_shared_loader_factory, &mock_delegate);
+  GURL query_url = fetcher.BuildQueryURL();
+
+  EXPECT_EQ("https", query_url.scheme());
+  EXPECT_EQ("www.googleapis.com", query_url.host());
+  EXPECT_EQ("/affiliation/v1/affiliation:lookupByHashPrefix", query_url.path());
+}
+
+}  // namespace password_manager