[Not for review] record detailed time breakdown of SW related requests.

content/renderer/service_worker/service_worker_context_client.cc

Index: content/renderer/service_worker/service_worker_context_client.cc
diff --git a/content/renderer/service_worker/service_worker_context_client.cc b/content/renderer/service_worker/service_worker_context_client.cc
index b07de5d43b1aee04581ad908938827603fc102c3..de18b61dca441a239c243a93d79a277915a17f3f 100644
--- a/content/renderer/service_worker/service_worker_context_client.cc
+++ b/content/renderer/service_worker/service_worker_context_client.cc
@@ -685,7 +685,7 @@ void ServiceWorkerContextClient::respondToFetchEvent(
   Send(new ServiceWorkerHostMsg_FetchEventResponse(
       GetRoutingID(), fetch_event_id,
       SERVICE_WORKER_FETCH_EVENT_RESULT_FALLBACK, ServiceWorkerResponse(),
-      base::Time::FromDoubleT(event_dispatch_time)));
+      base::Time::FromDoubleT(event_dispatch_time), base::TimeTicks::Now()));
 }
 
 void ServiceWorkerContextClient::respondToFetchEvent(
@@ -696,7 +696,7 @@ void ServiceWorkerContextClient::respondToFetchEvent(
       GetRoutingID(), fetch_event_id,
       SERVICE_WORKER_FETCH_EVENT_RESULT_RESPONSE,
       GetServiceWorkerResponseFromWebResponse(web_response),
-      base::Time::FromDoubleT(event_dispatch_time)));
+      base::Time::FromDoubleT(event_dispatch_time), base::TimeTicks::Now()));
 }
 
 void ServiceWorkerContextClient::didHandleFetchEvent(
@@ -967,7 +967,9 @@ void ServiceWorkerContextClient::DispatchFetchEvent(
   TRACE_EVENT0("ServiceWorker",
                "ServiceWorkerContextClient::DispatchFetchEvent");
   context_->fetch_event_callbacks.AddWithID(
-      base::MakeUnique<FetchCallback>(callback), fetch_event_id);
+      base::MakeUnique<FetchCallback>(
+          base::Bind(callback, base::TimeTicks::Now())),
+      fetch_event_id);
   if (preload_request) {
     context_->preload_requests.AddWithID(std::move(preload_request),
                                          fetch_event_id);