Introduce ServiceWorker.EventDispatchingDelay UMA

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 192 matching lines @@
   static void RecordActivateEventStatus(ServiceWorkerStatusCode status,
                                         bool is_shutdown);
   static void RecordInstallEventStatus(ServiceWorkerStatusCode status);
 
   // Records how much of dispatched events are handled while a Service
   // Worker is awake (i.e. after it is woken up until it gets stopped).
   static void RecordEventHandledRatio(EventType event,
                                       size_t handled_events,
                                       size_t fired_events);
 
+  // Records the time taken between sending a FetchEvent IPC from the browser
+  // process to a Service Worker and executing the fetch event handler in the
+  // Service Worker.
+  static void RecordFetchEventDispatchingDelay(base::TimeDelta time,
+                                               Site site_for_metrics);
+
   // Records the precision of the speculative launch of Service Workers for
   // each navigation hint type when the worker is stopped. If there was no
   // main/sub frame fetch event fired on the worker, |frame_fetch_event_fired|
   // is false. This means that the speculative launch wasn't helpful.
   static void RecordNavigationHintPrecision(EventType start_worker_purpose,
                                             bool frame_fetch_event_fired);
 
   // Records how often a dispatched event times out.
   static void RecordEventTimeout(EventType event);
 
@@ skipping 48 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_