Add tests for console messages of waitUntil() and respondWith()

content/test/data/service_worker/worker_install_rejected.js

Index: content/test/data/service_worker/worker_install_rejected.js
diff --git a/content/test/data/service_worker/worker_install_rejected.js b/content/test/data/service_worker/worker_install_rejected.js
index c57ab6f542fa3e67484d9535f5fffec968d302ff..1959277a158ea4d5c7c8df40648aa276efe67079 100644
--- a/content/test/data/service_worker/worker_install_rejected.js
+++ b/content/test/data/service_worker/worker_install_rejected.js
@@ -4,6 +4,6 @@
 
 this.oninstall = function(event) {
     event.waitUntil(new Promise(function(resolve, reject) {
-        setTimeout(reject, 5);
+        setTimeout(function() { reject("Rejecting oninstall event"); }, 5);
     }));
 };