Make //content responsible for generating notification Ids

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 3806ef8644b3308ffea21ec65fb2e2f164bae929..62f2465b1fdf9194b31fd0acca5b51eb19db6315 100644
--- a/content/renderer/service_worker/service_worker_context_client.h
+++ b/content/renderer/service_worker/service_worker_context_client.h
@@ -215,13 +215,13 @@ class ServiceWorkerContextClient
                     const ServiceWorkerFetchRequest& request);
   void OnNotificationClickEvent(
       int request_id,
-      int64_t persistent_notification_id,
+      const std::string& notification_id,
       const PlatformNotificationData& notification_data,
       int action_index);
   void OnPushEvent(int request_id, const PushEventPayload& payload);
   void OnNotificationCloseEvent(
       int request_id,
-      int64_t persistent_notification_id,
+      const std::string& notification_id,
       const PlatformNotificationData& notification_data);
 
   void OnDidGetClient(int request_id, const ServiceWorkerClientInfo& client);