[Offline pages]: Implement background loader to save on last retry, and record last retry success U…

components/offline_pages/core/background/request_coordinator_event_logger.cc

Index: components/offline_pages/core/background/request_coordinator_event_logger.cc
diff --git a/components/offline_pages/core/background/request_coordinator_event_logger.cc b/components/offline_pages/core/background/request_coordinator_event_logger.cc
index 0820146f0acba76954d98407d8d841b037faf575..33b697ad1f289c6becc89282b39b454bfdb28016 100644
--- a/components/offline_pages/core/background/request_coordinator_event_logger.cc
+++ b/components/offline_pages/core/background/request_coordinator_event_logger.cc
@@ -41,6 +41,8 @@ static std::string OfflinerRequestStatusToString(
       return "QUEUE_UPDATE_FAILED";
     case Offliner::BACKGROUND_SCHEDULER_CANCELED:
       return "BACKGROUND_SCHEDULER_CANCELED";
+    case Offliner::SAVED_ON_LAST_RETRY:
+      return "SAVED_ON_LAST_RETRY";
     default:
       NOTREACHED();
       return std::to_string(static_cast<int>(request_status));