Bug 1261814: Use the presence of the content global, and not any random global, to determine whether to run the close handler. r=bz

dom/workers/WorkerPrivate.cpp

@@ -5702,7 +5702,7 @@ WorkerPrivate::NotifyInternal(JSContext* aCx, Status aStatus)
 
   // If the worker script never ran, or failed to compile, we don't need to do
   // anything else, except pretend that we ran the close handler.
-  if (!JS::CurrentGlobalOrNull(aCx)) {
+  if (!GlobalScope()) {
     mCloseHandlerStarted = true;
     mCloseHandlerFinished = true;
     return true;