BackgroundSync sync events need to be ExtendableEvents, content side cleanup

content/renderer/service_worker/service_worker_context_client.cc

Index: content/renderer/service_worker/service_worker_context_client.cc
diff --git a/content/renderer/service_worker/service_worker_context_client.cc b/content/renderer/service_worker/service_worker_context_client.cc
index ee0ffdeaff24ede6607f1599067d14d4ef5343d3..93edf9847eca5c96a45939f8004dace04551a531 100644
--- a/content/renderer/service_worker/service_worker_context_client.cc
+++ b/content/renderer/service_worker/service_worker_context_client.cc
@@ -518,11 +518,6 @@ void ServiceWorkerContextClient::didHandlePushEvent(
       GetRoutingID(), request_id, result));
 }
 
-// TODO(chasej): crbug.com/486890 - Remove when matching blink changes land
-void ServiceWorkerContextClient::didHandleSyncEvent(int request_id) {
-  didHandleSyncEvent(request_id, blink::WebServiceWorkerEventResultCompleted);
-}
-
 void ServiceWorkerContextClient::didHandleSyncEvent(
     int request_id,
     blink::WebServiceWorkerEventResult result) {