Add ref count to service workers for extension API.

content/browser/service_worker/service_worker_version.cc

Index: content/browser/service_worker/service_worker_version.cc
diff --git a/content/browser/service_worker/service_worker_version.cc b/content/browser/service_worker/service_worker_version.cc
index ed7ae82ea0a1579398af3bf3e96a88cdf88807ee..cf2bb0bd85ce6bdfc3a3fd96e465113b4e4b7700 100644
--- a/content/browser/service_worker/service_worker_version.cc
+++ b/content/browser/service_worker/service_worker_version.cc
@@ -55,7 +55,7 @@ using StatusCallback = ServiceWorkerVersion::StatusCallback;
 namespace {
 
 // Time to wait until stopping an idle worker.
-const int kIdleWorkerTimeoutSeconds = 30;
+const int kIdleWorkerTimeoutSeconds = 3;
 
 // Default delay for scheduled update.
 const int kUpdateDelaySeconds = 1;
@@ -192,7 +192,7 @@ int NextTraceId() {
 
 }  // namespace
 
-const int ServiceWorkerVersion::kTimeoutTimerDelaySeconds = 30;
+const int ServiceWorkerVersion::kTimeoutTimerDelaySeconds = 3;

[falken, 2016/07/22 05:06:02]

Are these timer changes just for proof of concept?

I'm not sure we want to do this in production. The timers are intentionally slow
so SW doesn't cause too much work in the browser process and we also keep SW
alive for a while in case it'll need to be used again (for example, initial page
load, user looks at page for a while, then clicks a link).

[lazyboy, 2016/07/26 17:45:48]

Yes, these are entirely for proof of concept, especially for running the test
locally for now.

I need to find a better way to test the timeout behavior in tests. Once the CL
progresses, I'll do so.

 const int ServiceWorkerVersion::kStartInstalledWorkerTimeoutSeconds = 60;
 const int ServiceWorkerVersion::kStartNewWorkerTimeoutMinutes = 5;
 const int ServiceWorkerVersion::kRequestTimeoutMinutes = 5;
@@ -1412,6 +1412,7 @@ void ServiceWorkerVersion::SetTimeoutTimerInterval(base::TimeDelta interval) {
 }
 
 void ServiceWorkerVersion::OnTimeoutTimer() {
+  LOG(ERROR) << "ServiceWorkerVersion::OnTimeoutTimer";
   DCHECK(running_status() == EmbeddedWorkerStatus::STARTING ||
          running_status() == EmbeddedWorkerStatus::RUNNING ||
          running_status() == EmbeddedWorkerStatus::STOPPING)
@@ -1518,6 +1519,7 @@ void ServiceWorkerVersion::OnPingTimeout() {
 }
 
 void ServiceWorkerVersion::StopWorkerIfIdle() {
+  LOG(ERROR) << "ServiceWorkerVersion::StopWorkerIfIdle";
   if (HasWork() && !ping_controller_->IsTimedOut())
     return;
   if (running_status() == EmbeddedWorkerStatus::STOPPED ||