[NTP Snippets] Refactor background scheduling for remote suggestions

components/ntp_snippets/content_suggestions_service.cc

Index: components/ntp_snippets/content_suggestions_service.cc
diff --git a/components/ntp_snippets/content_suggestions_service.cc b/components/ntp_snippets/content_suggestions_service.cc
index 5cd19fd2c70fd03eee9b33759ee80ec3a1c7c29f..74d58f16eea93535afbafdfcf0f2a244bb5f59a6 100644
--- a/components/ntp_snippets/content_suggestions_service.cc
+++ b/components/ntp_snippets/content_suggestions_service.cc
@@ -29,7 +29,8 @@ ContentSuggestionsService::ContentSuggestionsService(
     : state_(state),
       signin_observer_(this),
       history_service_observer_(this),
-      ntp_snippets_service_(nullptr),
+      remote_suggestions_provider_(nullptr),
+      persistent_scheduler_listener_(nullptr),
       pref_service_(pref_service),
       user_classifier_(pref_service) {
   // Can be null in tests.
@@ -47,7 +48,8 @@ ContentSuggestionsService::ContentSuggestionsService(
 ContentSuggestionsService::~ContentSuggestionsService() = default;
 
 void ContentSuggestionsService::Shutdown() {
-  ntp_snippets_service_ = nullptr;
+  remote_suggestions_provider_ = nullptr;
+  persistent_scheduler_listener_ = nullptr;
   suggestions_by_category_.clear();
   providers_by_category_.clear();
   categories_.clear();
@@ -223,6 +225,12 @@ void ContentSuggestionsService::Fetch(
   providers_it->second->Fetch(category, known_suggestion_ids, callback);
 }
 
+void ContentSuggestionsService::ReloadSuggestions() {
+  for (const auto& category_provider_pair : providers_by_category_) {
+    category_provider_pair.second->ReloadSuggestions();
+  }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Private methods