Add a return when StopWorker is called after service worker is stopped

content/renderer/service_worker/embedded_worker_instance_client_impl.cc

Index: content/renderer/service_worker/embedded_worker_instance_client_impl.cc
diff --git a/content/renderer/service_worker/embedded_worker_instance_client_impl.cc b/content/renderer/service_worker/embedded_worker_instance_client_impl.cc
index 8bea7d38ed6d24fc45cc24fa3cb41febd92f4e94..6ef334bb81e52f7781cd00dbe77d92a3857d94a6 100644
--- a/content/renderer/service_worker/embedded_worker_instance_client_impl.cc
+++ b/content/renderer/service_worker/embedded_worker_instance_client_impl.cc
@@ -44,6 +44,7 @@ void EmbeddedWorkerInstanceClientImpl::StopWorkerCompleted() {
   TRACE_EVENT0("ServiceWorker",
                "EmbeddedWorkerInstanceClientImpl::StopWorkerCompleted");
   stop_callback_.Reset();
+  wrapper_ = nullptr;
 }
 
 void EmbeddedWorkerInstanceClientImpl::StartWorker(
@@ -73,7 +74,7 @@ void EmbeddedWorkerInstanceClientImpl::StopWorker(
   DCHECK(ChildThreadImpl::current());
   DCHECK(embedded_worker_id_);
   // StopWorker is possible to be called twice.
-  if (stop_callback_) {
+  if (stop_callback_ || !wrapper_) {
     LOG(WARNING) << "Got StopWorker for stopping worker";
     return;
   }