Introduce ServiceWorker.ActivatedWorkerPreparationForMainFrame.Time UMA.

content/browser/service_worker/service_worker_url_request_job.cc

Index: content/browser/service_worker/service_worker_url_request_job.cc
diff --git a/content/browser/service_worker/service_worker_url_request_job.cc b/content/browser/service_worker/service_worker_url_request_job.cc
index e06e5935e242c6eada3978d177e1aeeb823458eb..53fe6973bd37ff6312aee772156abe5f015bb97e 100644
--- a/content/browser/service_worker/service_worker_url_request_job.cc
+++ b/content/browser/service_worker/service_worker_url_request_job.cc
@@ -22,6 +22,7 @@
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "content/browser/resource_context_impl.h"
+#include "content/browser/service_worker/embedded_worker_instance.h"
 #include "content/browser/service_worker/service_worker_fetch_dispatcher.h"
 #include "content/browser/service_worker/service_worker_provider_host.h"
 #include "content/browser/service_worker/service_worker_response_info.h"
@@ -632,9 +633,18 @@ void ServiceWorkerURLRequestJob::CreateRequestBodyBlob(std::string* blob_uuid,
   *blob_size = total_size;
 }
 
-void ServiceWorkerURLRequestJob::DidPrepareFetchEvent() {
+void ServiceWorkerURLRequestJob::DidPrepareFetchEvent(
+    const scoped_refptr<ServiceWorkerVersion>& version) {

[falken, 2016/06/07 06:20:30]

const scoped_refptr& is deprecated. Now we use scoped_refptr with std::move if
appropriate.

http://www.chromium.org/developers/smart-pointer-guidelines#TOC-What-about-pa...

[horo, 2016/06/07 06:58:48]

Done.

   worker_ready_time_ = base::TimeTicks::Now();
   load_timing_info_.send_start = worker_ready_time_;
+  if (resource_type_ == RESOURCE_TYPE_MAIN_FRAME && worker_already_activated_ &&
+      !(version->skip_recording_startup_time() &&
+        initial_worker_status_ != EmbeddedWorkerStatus::RUNNING) &&

[falken, 2016/06/07 06:20:30]

Doesn't that mean
ServiceWorker.ActivatedWorkerPreparationForMainFrame.Time_RunningWorker is never
recorded?

[horo, 2016/06/07 06:58:48]

"!(version->skip_recording_startup_time() &&
   initial_worker_status_ != EmbeddedWorkerStatus::RUNNING)" means:

If the DevTools was attached and the worker is started for this URL request, we
don't record the metric.

+      !ServiceWorkerMetrics::ShouldExcludeURLFromHistogram(request()->url())) {
+    ServiceWorkerMetrics::RecordActivatedWorkerPreparationTimeForMainFrame(
+        worker_ready_time_ - request()->creation_time(), initial_worker_status_,
+        version->embedded_worker()->start_situation());
+  }
 }
 
 void ServiceWorkerURLRequestJob::DidDispatchFetchEvent(
@@ -962,11 +972,15 @@ void ServiceWorkerURLRequestJob::RequestBodyBlobsCompleted(bool success) {
     return;
   }
 
+  worker_already_activated_ =
+      active_worker->status() == ServiceWorkerVersion::ACTIVATED;
+  initial_worker_status_ = active_worker->running_status();
+
   DCHECK(!fetch_dispatcher_);
   fetch_dispatcher_.reset(new ServiceWorkerFetchDispatcher(
       CreateFetchRequest(), active_worker, resource_type_,
       base::Bind(&ServiceWorkerURLRequestJob::DidPrepareFetchEvent,
-                 weak_factory_.GetWeakPtr()),
+                 weak_factory_.GetWeakPtr(), active_worker),
       base::Bind(&ServiceWorkerURLRequestJob::DidDispatchFetchEvent,
                  weak_factory_.GetWeakPtr())));
   worker_start_time_ = base::TimeTicks::Now();