[ServiceWorker] Convert ping-pong IPC into mojo interface ServiceWorkerEventDispatcher

content/renderer/service_worker/service_worker_context_client.h

Index: content/renderer/service_worker/service_worker_context_client.h
diff --git a/content/renderer/service_worker/service_worker_context_client.h b/content/renderer/service_worker/service_worker_context_client.h
index cc7ae1dac66f4828e89e6baca45c590baa7a560f..f0dfb9263b477c4fe3a750c840e39c8412362b1f 100644
--- a/content/renderer/service_worker/service_worker_context_client.h
+++ b/content/renderer/service_worker/service_worker_context_client.h
@@ -239,6 +239,7 @@ class ServiceWorkerContextClient : public blink::WebServiceWorkerContextClient,
   void DispatchPaymentRequestEvent(
       payments::mojom::PaymentAppRequestPtr app_request,
       const DispatchPaymentRequestEventCallback& callback) override;
+  void Ping(const PingCallback& callback) override;
 
   void OnInstallEvent(int request_id);
   void OnNotificationClickEvent(
@@ -268,8 +269,6 @@ class ServiceWorkerContextClient : public blink::WebServiceWorkerContextClient,
   void OnClaimClientsError(int request_id,
                            blink::WebServiceWorkerError::ErrorType error_type,
                            const base::string16& message);
-  void OnPing();
-
   // Called to resolve the FetchEvent.preloadResponse promise.
   void OnNavigationPreloadResponse(
       int fetch_event_id,