ServiceWorker: Add UMA to measure execution times of oninstall/onfetch

content/browser/service_worker/service_worker_dispatcher_host.cc

Index: content/browser/service_worker/service_worker_dispatcher_host.cc
diff --git a/content/browser/service_worker/service_worker_dispatcher_host.cc b/content/browser/service_worker/service_worker_dispatcher_host.cc
index da7979b575e2a67efa4f607a45e7324a76f435ab..77cf793d9df83b389f4baa4501f30515f94fbf33 100644
--- a/content/browser/service_worker/service_worker_dispatcher_host.cc
+++ b/content/browser/service_worker/service_worker_dispatcher_host.cc
@@ -13,6 +13,7 @@
 #include "content/browser/service_worker/service_worker_context_core.h"
 #include "content/browser/service_worker/service_worker_context_wrapper.h"
 #include "content/browser/service_worker/service_worker_handle.h"
+#include "content/browser/service_worker/service_worker_metrics.h"
 #include "content/browser/service_worker/service_worker_registration.h"
 #include "content/browser/service_worker/service_worker_registration_handle.h"
 #include "content/browser/service_worker/service_worker_utils.h"
@@ -251,6 +252,9 @@ void ServiceWorkerDispatcherHost::OnRegisterServiceWorker(
                            request_id,
                            "Pattern", pattern.spec(),
                            "Script URL", script_url.spec());
+  registration_start_timings_.AddWithID(
+      new base::TimeTicks(base::TimeTicks::Now()), request_id);
+
   GetContext()->RegisterServiceWorker(
       pattern,
       script_url,
@@ -479,6 +483,10 @@ void ServiceWorkerDispatcherHost::RegistrationComplete(
     ServiceWorkerStatusCode status,
     int64 registration_id,
     int64 version_id) {
+  scoped_ptr<base::TimeTicks> registration_start_timing(
+    registration_start_timings_.Lookup(request_id));
+  registration_start_timings_.Remove(request_id);
+
   if (!GetContext())
     return;
 
@@ -503,6 +511,8 @@ void ServiceWorkerDispatcherHost::RegistrationComplete(
                          request_id,
                          "Registration ID", registration_id,
                          "Version ID", version_id);
+  ServiceWorkerMetrics::MeasureRegistrationTime(
+      base::TimeTicks::Now() - *registration_start_timing);
 }
 
 void ServiceWorkerDispatcherHost::OnWorkerReadyForInspection(