FetchMore functionality backend

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..5df3723b7d5663817b282aff5e78f604bf9cb6c1 100644
--- a/components/ntp_snippets/content_suggestions_service.cc
+++ b/components/ntp_snippets/content_suggestions_service.cc
@@ -195,6 +195,15 @@ void ContentSuggestionsService::RegisterProvider(
   providers_.push_back(std::move(provider));
 }
 
+void ContentSuggestionsService::FetchMore(const Category& category,
+                                          FetchedMoreCallback callback) {
+  auto providers_it = providers_by_category_.find(category);
+  if (providers_it == providers_by_category_.end())
+    return;
+
+  providers_it->second->FetchMore(category, callback);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Private methods