ServiceWorker: Keep the worker alive until FetchEvent.waitUntil settles

content/browser/service_worker/service_worker_metrics.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_METRICS_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_METRICS_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
@@ skipping 62 matching lines @@
   // Used for UMA. Append-only.
   enum class StopStatus {
     NORMAL,
     DETACH_BY_REGISTRY,
     TIMEOUT,
     // Add new types here.
     NUM_TYPES
   };
 
   // Used for UMA. Append-only.
+  // This class is used to indicate which event is fired/finished. Most events
+  // have only one request that starts event and one response that finishes

[falken, 2016/06/22 05:53:33]

nit: s/starts event/starts the event and s/finishes event/finishes the event

[shimazu, 2016/06/22 07:13:39]

Done.

+  // event, but the fetch and the foreign fetch event have two responses, so
+  // there are two types of EventType to break down the measurement into two:
+  // FETCH/FOREIGN_FETCH and FETCH_WAITUNTIL/FOREIGN_FETCH_WAITUNTIL.
+  // Moreover, FETCH is separated into the four: MAIN_FRAME, SUB_FRAME,
+  // SHARED_WORKER and SUB_RESOURCE for more detailed UMA.
   enum class EventType {
     ACTIVATE = 0,
     INSTALL = 1,
     // FETCH = 2,  // Obsolete
     SYNC = 3,
     NOTIFICATION_CLICK = 4,
     PUSH = 5,
     // GEOFENCING = 6,  // Obsolete
     // SERVICE_PORT_CONNECT = 7,  // Obsolete
     MESSAGE = 8,
     NOTIFICATION_CLOSE = 9,
     FETCH_MAIN_FRAME = 10,
     FETCH_SUB_FRAME = 11,
     FETCH_SHARED_WORKER = 12,
     FETCH_SUB_RESOURCE = 13,
     UNKNOWN = 14,  // Used when event type is not known.
     FOREIGN_FETCH = 15,
+    FETCH_WAITUNTIL = 16,
+    FOREIGN_FETCH_WAITUNTIL = 17,
     // Add new events to record here.
     NUM_TYPES
   };
 
   // Used for UMA. Append only.
   enum class Site {
     OTHER,  // Obsolete
     NEW_TAB_PAGE,
     WITH_FETCH_HANDLER,
     WITHOUT_FETCH_HANDLER,
@@ skipping 130 matching lines @@
   static void RecordStartStatusAfterFailure(int failure_count,
                                             ServiceWorkerStatusCode status);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ServiceWorkerMetrics);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_METRICS_H_