[NTP::SectionOrder] Replace CategoryFactory with a category ranker.

This CL:
1) Adds CategoryRanker interface;
2) Adds a default constant category ranker implementation (based on
   CategoryFactory);
3) Replaces CategoryFactory with a new ranker;
4) Factory methods are moved to Category.

This is the initial step of moving to personalised section order.

BUG=673659

Review-Url: https://codereview.chromium.org/2568033005
Cr-Commit-Position: refs/heads/master@{#439451}

chrome/browser/android/ntp/ntp_snippets_bridge.cc

@@ -173,12 +173,8 @@ static void OnSuggestionTargetVisited(JNIEnv* env,
                                       const JavaParamRef<jclass>& caller,
                                       jint j_category_id,
                                       jlong visit_time_ms) {
-  Profile* profile = ProfileManager::GetLastUsedProfile();
-  ntp_snippets::ContentSuggestionsService* content_suggestions_service =
-      ContentSuggestionsServiceFactory::GetForProfile(profile);
   ntp_snippets::metrics::OnSuggestionTargetVisited(
-      content_suggestions_service->category_factory()->FromIDValue(
-          j_category_id),
+      Category::FromIDValue(j_category_id),
       base::TimeDelta::FromMilliseconds(visit_time_ms));
 }
 
@@ -218,7 +214,7 @@ int NTPSnippetsBridge::GetCategoryStatus(JNIEnv* env,
                                          const JavaParamRef<jobject>& obj,
                                          jint j_category_id) {
   return static_cast<int>(content_suggestions_service_->GetCategoryStatus(
-      CategoryFromIDValue(j_category_id)));
+      Category::FromIDValue(j_category_id)));
 }
 
 base::android::ScopedJavaLocalRef<jobject> NTPSnippetsBridge::GetCategoryInfo(
@@ -227,7 +223,7 @@ base::android::ScopedJavaLocalRef<jobject> NTPSnippetsBridge::GetCategoryInfo(
     jint j_category_id) {
   base::Optional<CategoryInfo> info =
       content_suggestions_service_->GetCategoryInfo(
-          CategoryFromIDValue(j_category_id));
+          Category::FromIDValue(j_category_id));
   if (!info) {
     return base::android::ScopedJavaLocalRef<jobject>(env, nullptr);
   }
@@ -243,7 +239,7 @@ ScopedJavaLocalRef<jobject> NTPSnippetsBridge::GetSuggestionsForCategory(
     JNIEnv* env,
     const base::android::JavaParamRef<jobject>& obj,
     jint j_category_id) {
-  Category category = CategoryFromIDValue(j_category_id);
+  Category category = Category::FromIDValue(j_category_id);
   return ToJavaSuggestionList(
       env, category,
       content_suggestions_service_->GetSuggestionsForCategory(category));
@@ -257,7 +253,7 @@ void NTPSnippetsBridge::FetchSuggestionImage(
     const JavaParamRef<jobject>& j_callback) {
   base::android::ScopedJavaGlobalRef<jobject> callback(j_callback);
   content_suggestions_service_->FetchSuggestionImage(
-      ContentSuggestion::ID(CategoryFromIDValue(j_category_id),
+      ContentSuggestion::ID(Category::FromIDValue(j_category_id),
                             ConvertJavaStringToUTF8(env, id_within_category)),
       base::Bind(&NTPSnippetsBridge::OnImageFetched,
                  weak_ptr_factory_.GetWeakPtr(), callback));
@@ -272,7 +268,7 @@ void NTPSnippetsBridge::Fetch(
   AppendJavaStringArrayToStringVector(env, j_displayed_suggestions,
                                       &known_suggestion_ids);
 
-  Category category = CategoryFromIDValue(j_category_id);
+  Category category = Category::FromIDValue(j_category_id);
   content_suggestions_service_->Fetch(
       category, std::set<std::string>(known_suggestion_ids.begin(),
                                       known_suggestion_ids.end()),
@@ -288,7 +284,7 @@ void NTPSnippetsBridge::DismissSuggestion(
     jint j_category_id,
     jint category_position,
     const JavaParamRef<jstring>& id_within_category) {
-  Category category = CategoryFromIDValue(j_category_id);
+  Category category = Category::FromIDValue(j_category_id);
 
   content_suggestions_service_->DismissSuggestion(ContentSuggestion::ID(
       category, ConvertJavaStringToUTF8(env, id_within_category)));
@@ -310,7 +306,7 @@ void NTPSnippetsBridge::DismissSuggestion(
 void NTPSnippetsBridge::DismissCategory(JNIEnv* env,
                                         const JavaParamRef<jobject>& obj,
                                         jint j_category_id) {
-  Category category = CategoryFromIDValue(j_category_id);
+  Category category = Category::FromIDValue(j_category_id);
 
   content_suggestions_service_->DismissCategory(category);
 
@@ -337,7 +333,7 @@ void NTPSnippetsBridge::OnPageShown(
   std::vector<std::pair<Category, int>> suggestions_per_category;
   for (size_t i = 0; i < categories_int.size(); i++) {
     suggestions_per_category.push_back(
-        std::make_pair(CategoryFromIDValue(categories_int[i]),
+        std::make_pair(Category::FromIDValue(categories_int[i]),
                        suggestions_per_category_int[i]));
   }
   ntp_snippets::metrics::OnPageShown(suggestions_per_category);
@@ -358,7 +354,7 @@ void NTPSnippetsBridge::OnSuggestionShown(JNIEnv* env,
           ntp_snippets::prefs::kLastSuccessfulBackgroundFetchTime));
 
   ntp_snippets::metrics::OnSuggestionShown(
-      global_position, CategoryFromIDValue(j_category_id), category_position,
+      global_position, Category::FromIDValue(j_category_id), category_position,
       base::Time::FromJavaTime(publish_timestamp_ms),
       last_background_fetch_time, score);
   if (global_position == 0) {
@@ -376,9 +372,14 @@ void NTPSnippetsBridge::OnSuggestionOpened(JNIEnv* env,
                                            jfloat score,
                                            int windowOpenDisposition) {
   ntp_snippets::metrics::OnSuggestionOpened(
-      global_position, CategoryFromIDValue(j_category_id), category_position,
+      global_position, Category::FromIDValue(j_category_id), category_position,
       base::Time::FromJavaTime(publish_timestamp_ms), score,
       static_cast<WindowOpenDisposition>(windowOpenDisposition));
+  // TODO(vitaliii): Add ContentSuggestionsService::OnSuggestionOpened and
+  // notify the ranker and the classifier there instead. Do not expose both of
+  // them at all. See crbug.com/674080.
+  content_suggestions_service_->category_ranker()->OnSuggestionOpened(
+      Category::FromIDValue(j_category_id));
   content_suggestions_service_->user_classifier()->OnEvent(
       ntp_snippets::UserClassifier::Metric::SUGGESTIONS_USED);
 }
@@ -391,24 +392,24 @@ void NTPSnippetsBridge::OnSuggestionMenuOpened(JNIEnv* env,
                                                jlong publish_timestamp_ms,
                                                jfloat score) {
   ntp_snippets::metrics::OnSuggestionMenuOpened(
-      global_position, CategoryFromIDValue(j_category_id), category_position,
+      global_position, Category::FromIDValue(j_category_id), category_position,
       base::Time::FromJavaTime(publish_timestamp_ms), score);
 }
 
 void NTPSnippetsBridge::OnMoreButtonShown(JNIEnv* env,
                                           const JavaParamRef<jobject>& obj,
                                           jint j_category_id,
                                           jint position) {
-  ntp_snippets::metrics::OnMoreButtonShown(CategoryFromIDValue(j_category_id),
+  ntp_snippets::metrics::OnMoreButtonShown(Category::FromIDValue(j_category_id),
                                            position);
 }
 
 void NTPSnippetsBridge::OnMoreButtonClicked(JNIEnv* env,
                                             const JavaParamRef<jobject>& obj,
                                             jint j_category_id,
                                             jint position) {
-  ntp_snippets::metrics::OnMoreButtonClicked(CategoryFromIDValue(j_category_id),
-                                             position);
+  ntp_snippets::metrics::OnMoreButtonClicked(
+      Category::FromIDValue(j_category_id), position);
   content_suggestions_service_->user_classifier()->OnEvent(
       ntp_snippets::UserClassifier::Metric::SUGGESTIONS_USED);
 }
@@ -483,10 +484,6 @@ void NTPSnippetsBridge::OnSuggestionsFetched(
       ToJavaSuggestionList(env, category, suggestions));
 }
 
-Category NTPSnippetsBridge::CategoryFromIDValue(jint id) {
-  return content_suggestions_service_->category_factory()->FromIDValue(id);
-}
-
 // static
 bool NTPSnippetsBridge::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);

chrome/browser/android/ntp/ntp_snippets_bridge.h

@@ -149,8 +149,6 @@ class NTPSnippetsBridge
       ntp_snippets::Status status,
       std::vector<ntp_snippets::ContentSuggestion> suggestions);
 
-  ntp_snippets::Category CategoryFromIDValue(jint id);
-
   ntp_snippets::ContentSuggestionsService* content_suggestions_service_;
   history::HistoryService* history_service_;
   base::CancelableTaskTracker tracker_;

chrome/browser/ntp_snippets/content_suggestions_service_factory.cc

@@ -29,7 +29,7 @@
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "components/keyed_service/core/service_access_type.h"
 #include "components/ntp_snippets/bookmarks/bookmark_suggestions_provider.h"
-#include "components/ntp_snippets/category_factory.h"
+#include "components/ntp_snippets/category_rankers/constant_category_ranker.h"
 #include "components/ntp_snippets/content_suggestions_service.h"
 #include "components/ntp_snippets/features.h"
 #include "components/ntp_snippets/ntp_snippets_constants.h"
@@ -75,7 +75,6 @@ using content::BrowserThread;
 using history::HistoryService;
 using image_fetcher::ImageFetcherImpl;
 using ntp_snippets::BookmarkSuggestionsProvider;
-using ntp_snippets::CategoryFactory;
 using ntp_snippets::ContentSuggestionsService;
 using ntp_snippets::ForeignSessionsSuggestionsProvider;
 using ntp_snippets::NTPSnippetsFetcher;
@@ -100,52 +99,47 @@ void ClearScheduledTasks() {
 #if defined(OS_ANDROID)
 void RegisterRecentTabProvider(OfflinePageModel* offline_page_model,
                                ContentSuggestionsService* service,
-                               CategoryFactory* category_factory,
                                PrefService* pref_service) {
   auto provider = base::MakeUnique<RecentTabSuggestionsProvider>(
-      service, category_factory, offline_page_model, pref_service);
+      service, offline_page_model, pref_service);
   service->RegisterProvider(std::move(provider));
 }
 
 void RegisterDownloadsProvider(OfflinePageModel* offline_page_model,
                                DownloadManager* download_manager,
                                ContentSuggestionsService* service,
-                               CategoryFactory* category_factory,
                                PrefService* pref_service) {
   bool download_manager_ui_enabled =
       base::FeatureList::IsEnabled(chrome::android::kDownloadsUiFeature);
   auto provider = base::MakeUnique<DownloadSuggestionsProvider>(
-      service, category_factory, offline_page_model, download_manager,
-      pref_service, download_manager_ui_enabled);
+      service, offline_page_model, download_manager, pref_service,
+      download_manager_ui_enabled);
   service->RegisterProvider(std::move(provider));
 }
 #endif  // OS_ANDROID
 
 void RegisterBookmarkProvider(BookmarkModel* bookmark_model,
                               ContentSuggestionsService* service,
-                              CategoryFactory* category_factory,
                               PrefService* pref_service) {
   auto provider = base::MakeUnique<BookmarkSuggestionsProvider>(
-      service, category_factory, bookmark_model, pref_service);
+      service, bookmark_model, pref_service);
   service->RegisterProvider(std::move(provider));
 }
 
 #if defined(OS_ANDROID)
 void RegisterPhysicalWebPageProvider(
     ContentSuggestionsService* service,
-    CategoryFactory* category_factory,
     PhysicalWebDataSource* physical_web_data_source,
     PrefService* pref_service) {
   auto provider = base::MakeUnique<PhysicalWebPageSuggestionsProvider>(
-      service, category_factory, physical_web_data_source, pref_service);
+      service, physical_web_data_source, pref_service);
   service->RegisterProvider(std::move(provider));
 }
 #endif  // OS_ANDROID
 
 void RegisterArticleProvider(SigninManagerBase* signin_manager,
                              OAuth2TokenService* token_service,
                              ContentSuggestionsService* service,
-                             CategoryFactory* category_factory,
                              LanguageModel* language_model,
                              PrefService* pref_service,
                              Profile* profile) {
@@ -167,15 +161,14 @@ void RegisterArticleProvider(SigninManagerBase* signin_manager,
   bool is_stable_channel =
       chrome::GetChannel() == version_info::Channel::STABLE;
   auto provider = base::MakeUnique<RemoteSuggestionsProvider>(
-      service, service->category_factory(), pref_service,
-      g_browser_process->GetApplicationLocale(), service->user_classifier(),
-      scheduler, base::MakeUnique<NTPSnippetsFetcher>(
-                     signin_manager, token_service, request_context,
-                     pref_service, category_factory, language_model,
-                     base::Bind(&safe_json::SafeJsonParser::Parse),
-                     is_stable_channel ? google_apis::GetAPIKey()
-                                       : google_apis::GetNonStableAPIKey(),
-                     service->user_classifier()),
+      service, pref_service, g_browser_process->GetApplicationLocale(),
+      service->category_ranker(), service->user_classifier(), scheduler,
+      base::MakeUnique<NTPSnippetsFetcher>(
+          signin_manager, token_service, request_context, pref_service,
+          language_model, base::Bind(&safe_json::SafeJsonParser::Parse),
+          is_stable_channel ? google_apis::GetAPIKey()
+                            : google_apis::GetNonStableAPIKey(),
+          service->user_classifier()),
       base::MakeUnique<ImageFetcherImpl>(base::MakeUnique<ImageDecoderImpl>(),
                                          request_context.get()),
       base::MakeUnique<ImageDecoderImpl>(),
@@ -188,12 +181,11 @@ void RegisterArticleProvider(SigninManagerBase* signin_manager,
 
 void RegisterForeignSessionsProvider(SyncService* sync_service,
                                      ContentSuggestionsService* service,
-                                     CategoryFactory* category_factory,
                                      PrefService* pref_service) {
   std::unique_ptr<TabDelegateSyncAdapter> sync_adapter =
       base::MakeUnique<TabDelegateSyncAdapter>(sync_service);
   auto provider = base::MakeUnique<ForeignSessionsSuggestionsProvider>(
-      service, category_factory, std::move(sync_adapter), pref_service);
+      service, std::move(sync_adapter), pref_service);
   service->RegisterProvider(std::move(provider));
 }
 
@@ -251,16 +243,18 @@ KeyedService* ContentSuggestionsServiceFactory::BuildServiceInstanceFor(
   HistoryService* history_service = HistoryServiceFactory::GetForProfile(
       profile, ServiceAccessType::EXPLICIT_ACCESS);
   PrefService* pref_service = profile->GetPrefs();
-  auto* service = new ContentSuggestionsService(state, signin_manager,
-                                                history_service, pref_service);
+  auto category_ranker =
+      base::MakeUnique<ntp_snippets::ConstantCategoryRanker>();
+  auto* service =
+      new ContentSuggestionsService(state, signin_manager, history_service,
+                                    pref_service, std::move(category_ranker));
   if (state == State::DISABLED) {
     // Since we won't initialise the services, they won't get a chance to
     // unschedule their tasks. We do it explicitly here instead.
     ClearScheduledTasks();
     return service;
   }
 
-  CategoryFactory* category_factory = service->category_factory();
 #if defined(OS_ANDROID)
   OfflinePageModel* offline_page_model =
       OfflinePageModelFactory::GetForBrowserContext(profile);
@@ -281,8 +275,7 @@ KeyedService* ContentSuggestionsServiceFactory::BuildServiceInstanceFor(
 #if defined(OS_ANDROID)
   if (base::FeatureList::IsEnabled(
           ntp_snippets::kRecentOfflineTabSuggestionsFeature)) {
-    RegisterRecentTabProvider(offline_page_model, service, category_factory,
-                              pref_service);
+    RegisterRecentTabProvider(offline_page_model, service, pref_service);
   }
 
   bool show_asset_downloads =
@@ -293,35 +286,32 @@ KeyedService* ContentSuggestionsServiceFactory::BuildServiceInstanceFor(
     RegisterDownloadsProvider(
         show_offline_page_downloads ? offline_page_model : nullptr,
         show_asset_downloads ? download_manager : nullptr, service,
-        category_factory, pref_service);
+        pref_service);
   }
 #endif  // OS_ANDROID
 
   // |bookmark_model| can be null in tests.
   if (base::FeatureList::IsEnabled(ntp_snippets::kBookmarkSuggestionsFeature) &&
       bookmark_model) {
-    RegisterBookmarkProvider(bookmark_model, service, category_factory,
-                             pref_service);
+    RegisterBookmarkProvider(bookmark_model, service, pref_service);
   }
 
 #if defined(OS_ANDROID)
   if (base::FeatureList::IsEnabled(
           ntp_snippets::kPhysicalWebPageSuggestionsFeature)) {
-    RegisterPhysicalWebPageProvider(service, category_factory,
-                                    physical_web_data_source, pref_service);
+    RegisterPhysicalWebPageProvider(service, physical_web_data_source,
+                                    pref_service);
   }
 #endif  // OS_ANDROID
 
   if (base::FeatureList::IsEnabled(ntp_snippets::kArticleSuggestionsFeature)) {
     RegisterArticleProvider(signin_manager, token_service, service,
-                            category_factory, language_model, pref_service,
-                            profile);
+                            language_model, pref_service, profile);
   }
 
   if (base::FeatureList::IsEnabled(
           ntp_snippets::kForeignSessionsSuggestionsFeature)) {
-    RegisterForeignSessionsProvider(sync_service, service, category_factory,
-                                    pref_service);
+    RegisterForeignSessionsProvider(sync_service, service, pref_service);
   }
 
   return service;

chrome/browser/ntp_snippets/download_suggestions_provider.cc

@@ -129,14 +129,13 @@ std::unique_ptr<OfflinePageModelQuery> BuildOfflinePageDownloadsQuery(
 
 DownloadSuggestionsProvider::DownloadSuggestionsProvider(
     ContentSuggestionsProvider::Observer* observer,
-    ntp_snippets::CategoryFactory* category_factory,
     offline_pages::OfflinePageModel* offline_page_model,
     content::DownloadManager* download_manager,
     PrefService* pref_service,
     bool download_manager_ui_enabled)
-    : ContentSuggestionsProvider(observer, category_factory),
+    : ContentSuggestionsProvider(observer),
       category_status_(CategoryStatus::AVAILABLE_LOADING),
-      provided_category_(category_factory->FromKnownCategory(
+      provided_category_(Category::FromKnownCategory(
           ntp_snippets::KnownCategories::DOWNLOADS)),
       offline_page_model_(offline_page_model),
       download_manager_(download_manager),

chrome/browser/ntp_snippets/download_suggestions_provider.h

@@ -14,7 +14,6 @@
 #include "base/memory/weak_ptr.h"
 #include "components/ntp_snippets/callbacks.h"
 #include "components/ntp_snippets/category.h"
-#include "components/ntp_snippets/category_factory.h"
 #include "components/ntp_snippets/category_status.h"
 #include "components/ntp_snippets/content_suggestion.h"
 #include "components/ntp_snippets/content_suggestions_provider.h"
@@ -42,7 +41,6 @@ class DownloadSuggestionsProvider
  public:
   DownloadSuggestionsProvider(
       ContentSuggestionsProvider::Observer* observer,
-      ntp_snippets::CategoryFactory* category_factory,
       offline_pages::OfflinePageModel* offline_page_model,
       content::DownloadManager* download_manager,
       PrefService* pref_service,