[NTP Snippets] Refactor background scheduling for remote suggestions

components/ntp_snippets/content_suggestions_service.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 "components/ntp_snippets/content_suggestions_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 #include <utility>
@@ skipping 12 matching lines @@
 
 ContentSuggestionsService::ContentSuggestionsService(
     State state,
     SigninManagerBase* signin_manager,
     history::HistoryService* history_service,
     PrefService* pref_service,
     std::unique_ptr<CategoryRanker> category_ranker)
     : state_(state),
       signin_observer_(this),
       history_service_observer_(this),
-      ntp_snippets_service_(nullptr),
+      remote_suggestions_provider_(nullptr),
+      remote_suggestions_scheduler_(nullptr),
       pref_service_(pref_service),
       user_classifier_(pref_service),
       category_ranker_(std::move(category_ranker)) {
   // Can be null in tests.
   if (signin_manager) {
     signin_observer_.Add(signin_manager);
   }
 
   if (history_service) {
     history_service_observer_.Add(history_service);
   }
 
   RestoreDismissedCategoriesFromPrefs();
 }
 
 ContentSuggestionsService::~ContentSuggestionsService() = default;
 
 void ContentSuggestionsService::Shutdown() {
-  ntp_snippets_service_ = nullptr;
+  remote_suggestions_provider_ = nullptr;
+  remote_suggestions_scheduler_ = nullptr;
   suggestions_by_category_.clear();
   providers_by_category_.clear();
   categories_.clear();
   providers_.clear();
   state_ = State::DISABLED;
   for (Observer& observer : observers_) {
     observer.ContentSuggestionsServiceShutdown();
   }
 }
 
@@ skipping 155 matching lines @@
     const std::set<std::string>& known_suggestion_ids,
     const FetchDoneCallback& callback) {
   auto providers_it = providers_by_category_.find(category);
   if (providers_it == providers_by_category_.end()) {
     return;
   }
 
   providers_it->second->Fetch(category, known_suggestion_ids, callback);
 }
 
+void ContentSuggestionsService::ReloadSuggestions() {
+  for (const auto& provider : providers_) {
+    provider->ReloadSuggestions();
+  }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Private methods
 
 void ContentSuggestionsService::OnNewSuggestions(
     ContentSuggestionsProvider* provider,
     Category category,
     std::vector<ContentSuggestion> suggestions) {
   // Providers shouldn't call this when they're in a non-available state.
   DCHECK(
       IsCategoryStatusInitOrAvailable(provider->GetCategoryStatus(category)));
@@ skipping 257 matching lines @@
 void ContentSuggestionsService::StoreDismissedCategoriesToPrefs() {
   base::ListValue list;
   for (const auto& category_provider_pair : dismissed_providers_by_category_) {
     list.AppendInteger(category_provider_pair.first.id());
   }
 
   pref_service_->Set(prefs::kDismissedCategories, list);
 }
 
 }  // namespace ntp_snippets