[NTP Snippets] Metrics: switch over known categories

components/ntp_snippets/category_factory.cc

Index: components/ntp_snippets/category_factory.cc
diff --git a/components/ntp_snippets/category_factory.cc b/components/ntp_snippets/category_factory.cc
index 6ca67156b8295d1fcd448a8059e4107a5026d47c..55c89919aa2c156c0fb101c75c773a50c8026a04 100644
--- a/components/ntp_snippets/category_factory.cc
+++ b/components/ntp_snippets/category_factory.cc
@@ -16,6 +16,9 @@ CategoryFactory::CategoryFactory() {
   AddKnownCategory(KnownCategories::RECENT_TABS);
   AddKnownCategory(KnownCategories::BOOKMARKS);
   AddKnownCategory(KnownCategories::PHYSICAL_WEB_PAGES);
+
+  DCHECK_EQ(static_cast<size_t>(KnownCategories::LOCAL_CATEGORIES_COUNT),
+            ordered_categories_.size());
 }
 
 CategoryFactory::~CategoryFactory() {}