service worker: Add UMA for navigation preload response timing.

content/browser/service_worker/service_worker_url_request_job.cc

 // 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.
 
 #include "content/browser/service_worker/service_worker_url_request_job.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <map>
@@ skipping 537 matching lines @@
   if (resource_type_ != RESOURCE_TYPE_MAIN_FRAME)
     return;
   if (!worker_already_activated_)
     return;
   if (version->skip_recording_startup_time() &&
       initial_worker_status_ != EmbeddedWorkerStatus::RUNNING) {
     return;
   }
   if (version->should_exclude_from_uma())
     return;
+  worker_start_situation_ = version->embedded_worker()->start_situation();
   ServiceWorkerMetrics::RecordActivatedWorkerPreparationForMainFrame(
       worker_ready_time_ - request()->creation_time(), initial_worker_status_,
-      version->embedded_worker()->start_situation(), did_navigation_preload_);
+      worker_start_situation_, did_navigation_preload_);
+  MaybeReportNavigationPreloadMetrics();
 }
 
 void ServiceWorkerURLRequestJob::DidDispatchFetchEvent(
     ServiceWorkerStatusCode status,
     ServiceWorkerFetchEventResult fetch_result,
     const ServiceWorkerResponse& response,
     const scoped_refptr<ServiceWorkerVersion>& version) {
   // Do not clear |fetch_dispatcher_| if it has dispatched a navigation preload
   // request to keep the mojom::URLLoader related objects in it, because the
   // preload response might still need to be streamed even after calling
@@ skipping 307 matching lines @@
 
   DCHECK(!fetch_dispatcher_);
   fetch_dispatcher_.reset(new ServiceWorkerFetchDispatcher(
       CreateFetchRequest(), active_worker, resource_type_, timeout_,
       request()->net_log(),
       base::Bind(&ServiceWorkerURLRequestJob::DidPrepareFetchEvent,
                  weak_factory_.GetWeakPtr(), active_worker),
       base::Bind(&ServiceWorkerURLRequestJob::DidDispatchFetchEvent,
                  weak_factory_.GetWeakPtr())));
   worker_start_time_ = base::TimeTicks::Now();
-  did_navigation_preload_ =
-      fetch_dispatcher_->MaybeStartNavigationPreload(request());
+  did_navigation_preload_ = fetch_dispatcher_->MaybeStartNavigationPreload(
+      request(),
+      base::BindOnce(&ServiceWorkerURLRequestJob::OnNavigationPreloadResponse,
+                     weak_factory_.GetWeakPtr()));
   fetch_dispatcher_->Run();
 }
 
+void ServiceWorkerURLRequestJob::OnNavigationPreloadResponse() {
+  DCHECK(navigation_preload_response_time_.is_null());
+  navigation_preload_response_time_ = base::TimeTicks::Now();
+  MaybeReportNavigationPreloadMetrics();
+}
+
+void ServiceWorkerURLRequestJob::MaybeReportNavigationPreloadMetrics() {
+  if (worker_start_time_.is_null() || worker_ready_time_.is_null() ||
+      navigation_preload_response_time_.is_null()) {
+    return;
+  }
+  DCHECK(!reported_navigation_preload_metrics_);
+  reported_navigation_preload_metrics_ = true;
+
+  ServiceWorkerMetrics::RecordNavigationPreloadResponse(
+      worker_ready_time_ - worker_start_time_,
+      navigation_preload_response_time_ - worker_start_time_,
+      initial_worker_status_, worker_start_situation_);
+}
+
 }  // namespace content