[Icons NTP] FaviconService: Add method to retrieve large icon.

components/favicon/core/browser/favicon_service.h

Index: components/favicon/core/browser/favicon_service.h
diff --git a/components/favicon/core/browser/favicon_service.h b/components/favicon/core/browser/favicon_service.h
index 4149344915129b635a44bcce0468bc1f17a73e25..af2718c91220b7cdbc78e06b124972d186174dc6 100644
--- a/components/favicon/core/browser/favicon_service.h
+++ b/components/favicon/core/browser/favicon_service.h
@@ -128,6 +128,13 @@ class FaviconService : public KeyedService {
       const favicon_base::FaviconResultsCallback& callback,
       base::CancelableTaskTracker* tracker);
 
+  // Requests a generic large icon, not caring about which type.
+  base::CancelableTaskTracker::TaskId GetGenericLargeIconForPageURL(
+      const GURL& page_url,
+      int desired_size_in_pixel,
+      const favicon_base::FaviconRawBitmapCallback& callback,
+      base::CancelableTaskTracker* tracker);
+
   // Set the favicon mappings to |page_url| for |icon_types| in the history
   // database.
   // Sample |icon_urls|: