Create ServiceWorkerProviderHost before starting worker

content/browser/service_worker/embedded_worker_instance.h

Index: content/browser/service_worker/embedded_worker_instance.h
diff --git a/content/browser/service_worker/embedded_worker_instance.h b/content/browser/service_worker/embedded_worker_instance.h
index 737417c88ce30130b965a300a4ade9502c079d02..5f7e1ab7c684f5694e9f1c23cc99ed32524dfd28 100644
--- a/content/browser/service_worker/embedded_worker_instance.h
+++ b/content/browser/service_worker/embedded_worker_instance.h
@@ -228,7 +228,7 @@ class CONTENT_EXPORT EmbeddedWorkerInstance
   void OnScriptLoaded() override;
   // Notifies the corresponding provider host that the thread has started and is
   // ready to receive messages.
-  void OnThreadStarted(int thread_id, int provider_id) override;
+  void OnThreadStarted(int thread_id) override;
   void OnScriptLoadFailed() override;
   // Fires the callback passed to Start().
   void OnScriptEvaluated(bool success) override;
@@ -283,7 +283,10 @@ class CONTENT_EXPORT EmbeddedWorkerInstance
   std::unique_ptr<EmbeddedWorkerInstance::WorkerProcessHandle> process_handle_;
   int thread_id_;
 
-  // |client_| is used to send messages to the renderer process.
+  // |client_| is used to send messages to the renderer process. The browser
+  // process should not disconnect the pipe because other associated interfaces
+  // may be using it. The renderer process will disconnect the pipe when
+  // appropriate.
   mojom::EmbeddedWorkerInstanceClientPtr client_;
 
   // Binding for EmbeddedWorkerInstanceHost, runs on IO thread.