Change RunAfterStartWorker to not start the worker if it is already running.

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 b77ba3b06ec0ab61b2ac67e528e0bd38e8612d57..5a8c2e035fb5bb00fd800f0971d1aae78ad144d7 100644
--- a/content/browser/service_worker/service_worker_version.cc
+++ b/content/browser/service_worker/service_worker_version.cc
@@ -506,8 +506,13 @@ bool ServiceWorkerVersion::FinishRequest(int request_id) {
 }
 
 void ServiceWorkerVersion::RunAfterStartWorker(
-    const StatusCallback& error_callback,
-    const base::Closure& task) {
+    const base::Closure& task,
+    const StatusCallback& error_callback) {
+  if (running_status() == RUNNING) {
+    DCHECK(start_callbacks_.empty());
+    task.Run();
+    return;
+  }
   StartWorker(base::Bind(&RunTaskAfterStartWorker, weak_factory_.GetWeakPtr(),
                          error_callback, task));
 }