Service Worker: Don't record StartWorker metrics for a doomed worker.

content/browser/service_worker/service_worker_version.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_version.h"
 
 #include "base/command_line.h"
 #include "base/memory/ref_counted.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/stl_util.h"
@@ skipping 1522 matching lines @@
     !sync_callbacks_.IsEmpty() ||
     !notification_click_callbacks_.IsEmpty() ||
     !push_callbacks_.IsEmpty() ||
     !geofencing_callbacks_.IsEmpty() ||
     !cross_origin_connect_callbacks_.IsEmpty() ||
     !streaming_url_request_jobs_.empty();
 }
 
 void ServiceWorkerVersion::RecordStartWorkerResult(
     ServiceWorkerStatusCode status) {
+  base::TimeTicks start_time = start_time_;
+  ClearTick(&start_time_);
+
+  // Failing to start a doomed worker isn't interesting and very common when
+  // update dooms because the script is byte-to-byte identical.
+  if (is_doomed_)
+    return;
+
   UMA_HISTOGRAM_ENUMERATION("ServiceWorker.StartWorker.Status", status,
                             SERVICE_WORKER_ERROR_MAX_VALUE);
-  if (status == SERVICE_WORKER_OK && !start_time_.is_null()) {
+  if (status == SERVICE_WORKER_OK && !start_time.is_null()) {
     UMA_HISTOGRAM_MEDIUM_TIMES("ServiceWorker.StartWorker.Time",
-                               GetTickDuration(start_time_));
+                               GetTickDuration(start_time));
   }
 
-  ClearTick(&start_time_);
   if (status != SERVICE_WORKER_ERROR_TIMEOUT)
     return;
   EmbeddedWorkerInstance::StartingPhase phase =
       EmbeddedWorkerInstance::NOT_STARTING;
   EmbeddedWorkerInstance::Status running_status = embedded_worker_->status();
   // Build an artifical JavaScript exception to show in the ServiceWorker
   // log for developers; it's not user-facing so it's not a localized resource.
   std::string message = "ServiceWorker startup timed out. ";
   if (running_status != EmbeddedWorkerInstance::STARTING) {
     message.append("The worker had unexpected status: ");
@@ skipping 29 matching lines @@
     int request_id) {
   callbacks->Remove(request_id);
   if (is_doomed_) {
     // The stop should be already scheduled, but try to stop immediately, in
     // order to release worker resources soon.
     StopWorkerIfIdle();
   }
 }
 
 }  // namespace content