Add baked-in favicons for default popular sites on NTP

components/ntp_tiles/most_visited_sites_unittest.cc

Index: components/ntp_tiles/most_visited_sites_unittest.cc
diff --git a/components/ntp_tiles/most_visited_sites_unittest.cc b/components/ntp_tiles/most_visited_sites_unittest.cc
index 9c166090ffd9ef8ca301cfa2a2ae68e5254f7206..fdcaf1bb3bd6ae70eecdbb5be7e4e562346f76cf 100644
--- a/components/ntp_tiles/most_visited_sites_unittest.cc
+++ b/components/ntp_tiles/most_visited_sites_unittest.cc
@@ -234,7 +234,8 @@ class PopularSitesFactoryForTest {
     return base::MakeUnique<PopularSitesImpl>(
         worker_pool_owner_.pool().get(), prefs_,
         /*template_url_service=*/nullptr,
-        /*variations_service=*/nullptr, url_request_context_.get(),
+        /*variations_service=*/nullptr,
+        /*favicon_service=*/nullptr, url_request_context_.get(),
         /*directory=*/base::FilePath(), base::Bind(JsonUnsafeParser::Parse));
   }