Bug 1254741 P2 Don't aggressively terminate service workers when last controlled window is closed. r=baku

dom/workers/ServiceWorkerManager.cpp

@@ -1918,13 +1918,10 @@ ServiceWorkerManager::StopControllingADocument(ServiceWorkerRegistrationInfo* aR
     if (aRegistration->mPendingUninstall) {
       RemoveRegistration(aRegistration);
     } else {
-      // If the registration has an active worker that is running
-      // this might be a good time to stop it.
-      if (aRegistration->GetActive()) {
-        ServiceWorkerPrivate* serviceWorkerPrivate =
-          aRegistration->GetActive()->WorkerPrivate();
-        serviceWorkerPrivate->NoteStoppedControllingDocuments();
-      }
+      // We use to aggressively terminate the worker at this point, but it
+      // caused problems.  There are more uses for a service worker than actively
+      // controlled documents.  We need to let the worker naturally terminate
+      // in case its handling push events, message events, etc.
       aRegistration->TryToActivateAsync();
     }
   }

dom/workers/ServiceWorkerPrivate.cpp

@@ -84,7 +84,6 @@ NS_IMPL_ISUPPORTS0(KeepAliveToken)
 
 ServiceWorkerPrivate::ServiceWorkerPrivate(ServiceWorkerInfo* aInfo)
   : mInfo(aInfo)
-  , mIsPushWorker(false)
   , mDebuggerCount(0)
   , mTokenCount(0)
 {
@@ -1598,7 +1597,6 @@ ServiceWorkerPrivate::SpawnWorkerIfNeeded(WakeUpReason aWhy,
     return error.StealNSResult();
   }
 
-  mIsPushWorker = false;
   RenewKeepAliveToken(aWhy);
 
   return NS_OK;
@@ -1659,17 +1657,6 @@ ServiceWorkerPrivate::NoteDeadServiceWorkerInfo()
   TerminateWorker();
 }
 
-void
-ServiceWorkerPrivate::NoteStoppedControllingDocuments()
-{
-  AssertIsOnMainThread();
-  if (mIsPushWorker || mDebuggerCount) {
-    return;
-  }
-
-  TerminateWorker();
-}
-
 void
 ServiceWorkerPrivate::Activated()
 {
@@ -1801,10 +1788,6 @@ ServiceWorkerPrivate::RenewKeepAliveToken(WakeUpReason aWhy)
   // We should have an active worker if we're renewing the keep alive token.
   MOZ_ASSERT(mWorkerPrivate);
 
-  if (aWhy == PushEvent || aWhy == PushSubscriptionChangeEvent) {
-    mIsPushWorker = true;
-  }
-
   // If there is at least one debugger attached to the worker, the idle worker
   // timeout was canceled when the first debugger attached to the worker. It
   // should not be reset until the last debugger detaches from the worker.

dom/workers/ServiceWorkerPrivate.h

@@ -193,11 +193,6 @@ private:
 
   nsCOMPtr<nsITimer> mIdleWorkerTimer;
 
-  // We keep track if this worker received any push events since it was last
-  // woken up. The flag is reset to false every time a new WorkerPrivate
-  // is created.
-  bool mIsPushWorker;
-
   // We keep a token for |dom.serviceWorkers.idle_timeout| seconds to give the
   // worker a grace period after each event.
   RefPtr<KeepAliveToken> mKeepAliveToken;