[NTP::SectionOrder] Add ranker section to snippets internals.

components/ntp_snippets/category_rankers/fake_category_ranker.cc

Index: components/ntp_snippets/category_rankers/fake_category_ranker.cc
diff --git a/components/ntp_snippets/category_rankers/fake_category_ranker.cc b/components/ntp_snippets/category_rankers/fake_category_ranker.cc
index 94739a7b52523f8bbb7152e4dbdcab0e6acda074..42ce8bc9dab8ab32122fbba5006f75af5edc0610 100644
--- a/components/ntp_snippets/category_rankers/fake_category_ranker.cc
+++ b/components/ntp_snippets/category_rankers/fake_category_ranker.cc
@@ -42,6 +42,11 @@ void FakeCategoryRanker::InsertCategoryAfterIfNecessary(
   // Ignored.
 }
 
+std::vector<CategoryRanker::DebugDataItem> FakeCategoryRanker::GetDebugData() {
+  // Ignored.
+  return std::vector<CategoryRanker::DebugDataItem>();
+}
+
 void FakeCategoryRanker::OnSuggestionOpened(Category category) {
   // Ignored.
 }