Ensure the 1993 NTP logs to UMA Most Visited tiles that use the fallback thumbnail instead of the p…

chrome/browser/ui/webui/ntp/ntp_user_data_logger.h

Index: chrome/browser/ui/webui/ntp/ntp_user_data_logger.h
diff --git a/chrome/browser/ui/webui/ntp/ntp_user_data_logger.h b/chrome/browser/ui/webui/ntp/ntp_user_data_logger.h
index 41cd59d5fe7b594f498876b8963b1ea18cd38341..dc1df81ea28f2dd45a4f3b6f26d4e018fce78f3e 100644
--- a/chrome/browser/ui/webui/ntp/ntp_user_data_logger.h
+++ b/chrome/browser/ui/webui/ntp/ntp_user_data_logger.h
@@ -64,6 +64,14 @@ class NTPUserDataLogger
   // of a thumbnail image.
   size_t number_of_thumbnail_errors_;
 
+  // Total number of attempts made to load thumbnail images while providing a
+  // fallback thumbnail for this NTP session.
+  size_t number_of_fallback_thumbnails_requested_;
+
+  // Total number of errors that occurred while trying to load the primary
+  // thumbnail image and that caused a fallback to the secondary thumbnail.
+  size_t number_of_fallback_thumbnails_used_;
+
   // The URL of this New Tab Page - varies based on NTP version.
   GURL ntp_url_;