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

chrome/browser/ntp_snippets/download_suggestions_provider.cc

 // Copyright 2016 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 "chrome/browser/ntp_snippets/download_suggestions_provider.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 111 matching lines @@
   OfflinePageModelQueryBuilder builder;
   builder.RequireSupportedByDownload(
       OfflinePageModelQuery::Requirement::INCLUDE_MATCHING);
   return builder.Build(model->GetPolicyController());
 }
 
 }  // namespace
 
 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),
       pref_service_(pref_service),
       download_manager_ui_enabled_(download_manager_ui_enabled),
       weak_ptr_factory_(this) {
   observer->OnCategoryStatusChanged(this, provided_category_, category_status_);
 
   DCHECK(offline_page_model_ || download_manager_);
   if (offline_page_model_) {
@@ skipping 662 matching lines @@
 void DownloadSuggestionsProvider::UnregisterDownloadItemObservers() {
   DCHECK_NE(download_manager_, nullptr);
 
   std::vector<DownloadItem*> all_downloads;
   download_manager_->GetAllDownloads(&all_downloads);
 
   for (DownloadItem* item : all_downloads) {
     item->RemoveObserver(this);
   }
 }