service worker: Attribute purpose to start worker attempts for UMA

content/browser/service_worker/service_worker_register_job.cc

 // Copyright 2013 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_register_job.h"
 
 #include <stdint.h>
 
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 399 matching lines @@
   ResolvePromise(SERVICE_WORKER_OK, std::string(), registration());
 
   // "Fire a simple event named updatefound..."
   registration()->NotifyUpdateFound();
 
   // "Fire an event named install..."
   new_version()->RunAfterStartWorker(
       base::Bind(&ServiceWorkerRegisterJob::DispatchInstallEvent,
                  weak_factory_.GetWeakPtr()),
       base::Bind(&ServiceWorkerRegisterJob::OnInstallFinished,
-                 weak_factory_.GetWeakPtr()));
+                 weak_factory_.GetWeakPtr()),
+      ServiceWorkerMetrics::EventType::INSTALL);
 
   // A subsequent registration job may terminate our installing worker. It can
   // only do so after we've started the worker and dispatched the install
   // event, as those are atomic substeps in the [[Install]] algorithm.
   if (doom_installing_worker_)
     Complete(SERVICE_WORKER_ERROR_INSTALL_WORKER_FAILED);
 }
 
 void ServiceWorkerRegisterJob::DispatchInstallEvent() {
   DCHECK_EQ(ServiceWorkerVersion::INSTALLING, new_version()->status())
@@ skipping 159 matching lines @@
     ResolvePromise(SERVICE_WORKER_OK, std::string(), registration());
     Complete(SERVICE_WORKER_ERROR_EXISTS,
              "The updated worker is identical to the incumbent.");
     return;
   }
 
   new_version()->embedded_worker()->ResumeAfterDownload();
 }
 
 }  // namespace content