[NTP Snippets] Pass "no suggestions" message from the backend to the UI

components/ntp_snippets/content_suggestions_service_unittest.cc

Index: components/ntp_snippets/content_suggestions_service_unittest.cc
diff --git a/components/ntp_snippets/content_suggestions_service_unittest.cc b/components/ntp_snippets/content_suggestions_service_unittest.cc
index 8b27e51e62759cc71f60ab40f8d22909a887c13d..99d7a3fd0259b478e397167124398b0371f48247 100644
--- a/components/ntp_snippets/content_suggestions_service_unittest.cc
+++ b/components/ntp_snippets/content_suggestions_service_unittest.cc
@@ -60,7 +60,8 @@ class MockProvider : public ContentSuggestionsProvider {
 
   CategoryInfo GetCategoryInfo(Category category) override {
     return CategoryInfo(base::ASCIIToUTF16("Section title"),
-                        ContentSuggestionsCardLayout::FULL_CARD, true, true);
+                        ContentSuggestionsCardLayout::FULL_CARD, true, true,
+                        base::ASCIIToUTF16("No suggestions message"));
   }
 
   void FireSuggestionsChanged(