ServiceWorker: Insert TRACE_EVENT to watch a breakdown of the ServiceWorker's performance on chome:…

content/renderer/service_worker/embedded_worker_dispatcher.cc

Index: content/renderer/service_worker/embedded_worker_dispatcher.cc
diff --git a/content/renderer/service_worker/embedded_worker_dispatcher.cc b/content/renderer/service_worker/embedded_worker_dispatcher.cc
index 9630f3a18e4a814dd96462d674f9021d27688226..ad2287f2c294c529784e16181c37aa54437fb6ac 100644
--- a/content/renderer/service_worker/embedded_worker_dispatcher.cc
+++ b/content/renderer/service_worker/embedded_worker_dispatcher.cc
@@ -69,6 +69,7 @@ void EmbeddedWorkerDispatcher::WorkerContextDestroyed(
 void EmbeddedWorkerDispatcher::OnStartWorker(
     const EmbeddedWorkerMsg_StartWorker_Params& params) {
   DCHECK(!workers_.Lookup(params.embedded_worker_id));
+  TRACE_EVENT0("ServiceWorker", "EmbeddedWorkerDispatcher::OnStartWorker");
   RenderThread::Get()->EnsureWebKitInitialized();
   scoped_ptr<WorkerWrapper> wrapper(
       new WorkerWrapper(blink::WebEmbeddedWorker::create(
@@ -105,6 +106,7 @@ void EmbeddedWorkerDispatcher::OnStartWorker(
 }
 
 void EmbeddedWorkerDispatcher::OnStopWorker(int embedded_worker_id) {
+  TRACE_EVENT0("ServiceWorker", "EmbeddedWorkerDispatcher::OnStopWorker");
   WorkerWrapper* wrapper = workers_.Lookup(embedded_worker_id);
   if (!wrapper) {
     LOG(WARNING) << "Got OnStopWorker for nonexistent worker";
@@ -118,6 +120,8 @@ void EmbeddedWorkerDispatcher::OnStopWorker(int embedded_worker_id) {
 }
 
 void EmbeddedWorkerDispatcher::OnResumeAfterDownload(int embedded_worker_id) {
+  TRACE_EVENT0("ServiceWorker",
+               "EmbeddedWorkerDispatcher::OnResumeAfterDownload");
   WorkerWrapper* wrapper = workers_.Lookup(embedded_worker_id);
   if (!wrapper) {
     LOG(WARNING) << "Got OnResumeAfterDownload for nonexistent worker";