ServiceWorker: Keep the worker alive until FetchEvent.waitUntil settles

content/browser/service_worker/service_worker_metrics.cc

Index: content/browser/service_worker/service_worker_metrics.cc
diff --git a/content/browser/service_worker/service_worker_metrics.cc b/content/browser/service_worker/service_worker_metrics.cc
index a481b8bf03589ba0fdd19e209b76e7c869d1b9fe..ba70ae2df619411d1bdf8983c5cc30e4c9a3e123 100644
--- a/content/browser/service_worker/service_worker_metrics.cc
+++ b/content/browser/service_worker/service_worker_metrics.cc
@@ -106,6 +106,8 @@ const char* ServiceWorkerMetrics::EventTypeToString(EventType event_type) {
       return "Unknown";
     case EventType::FOREIGN_FETCH:
       return "Foreign Fetch";
+    case EventType::FETCH_WAITUNTIL:
+      return "Fetch WaitUntil";
     case EventType::NUM_TYPES:
       break;
   }
@@ -261,6 +263,11 @@ void ServiceWorkerMetrics::RecordStartWorkerStatus(
           "ServiceWorker.StartWorker.StatusByPurpose_FOREIGN_FETCH", status,
           SERVICE_WORKER_ERROR_MAX_VALUE);
       break;
+    case EventType::FETCH_WAITUNTIL:
+      UMA_HISTOGRAM_ENUMERATION(
+          "ServiceWorker.StartWorker.StatusByPurpose_FETCH_WAITUNTIL", status,
+          SERVICE_WORKER_ERROR_MAX_VALUE);
+      break;
     case EventType::NUM_TYPES:
       NOTREACHED();
       break;
@@ -371,6 +378,10 @@ void ServiceWorkerMetrics::RecordEventDuration(EventType event,
                                    time);
       }
       break;
+    case EventType::FETCH_WAITUNTIL:
+      UMA_HISTOGRAM_MEDIUM_TIMES("ServiceWorker.FetchEvent.WaitUntil.Time",
+                                 time);
+      break;
     case EventType::FOREIGN_FETCH:
       if (was_handled) {
         UMA_HISTOGRAM_MEDIUM_TIMES(