[NTP Snippets] NTPSnippetsService: notify about new suggestions only in changed categories

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 169afc154ded3cf2f0e9d32da806c5c97f65360d..eabac44ac042988c458d991c782a934f512a00c3 100644
--- a/components/ntp_snippets/content_suggestions_service.cc
+++ b/components/ntp_snippets/content_suggestions_service.cc
@@ -202,6 +202,10 @@ 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)));
+
   if (TryRegisterProviderForCategory(provider, category)) {
     NotifyCategoryStatusChanged(category);
   } else if (IsCategoryDismissed(category)) {