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

content/browser/service_worker/service_worker_version.h

Index: content/browser/service_worker/service_worker_version.h
diff --git a/content/browser/service_worker/service_worker_version.h b/content/browser/service_worker/service_worker_version.h
index 96c54453043cc695265eb67c440b6f02a2f8f172..b75d178ca3dfba3e0330541407531d59de8c4444 100644
--- a/content/browser/service_worker/service_worker_version.h
+++ b/content/browser/service_worker/service_worker_version.h
@@ -178,8 +178,8 @@ class CONTENT_EXPORT ServiceWorkerVersion
 
   // Starts the worker if it isn't already running, and calls |task| when the
   // worker is running, or |error_callback| if starting the worker failed.
-  void RunAfterStartWorker(const StatusCallback& error_callback,
-                           const base::Closure& task);
+  void RunAfterStartWorker(const base::Closure& task,
+                           const StatusCallback& error_callback);
 
   // Call this while the worker is running before dispatching an event to the
   // worker. This informs ServiceWorkerVersion about the event in progress.