Generalize validation of developer input for Web Notifications

LayoutTests/http/tests/notifications/serviceworkerregistration-document-actions-throw.html

Index: LayoutTests/http/tests/notifications/serviceworkerregistration-document-actions-throw.html
diff --git a/LayoutTests/http/tests/notifications/serviceworkerregistration-document-actions-throw.html b/LayoutTests/http/tests/notifications/serviceworkerregistration-document-actions-throw.html
index 8dba9b67e1c76c1c6bf62c368f86a5cc51345d5b..813d6499a83202908d40c12422dfef7a43c81556 100644
--- a/LayoutTests/http/tests/notifications/serviceworkerregistration-document-actions-throw.html
+++ b/LayoutTests/http/tests/notifications/serviceworkerregistration-document-actions-throw.html
@@ -59,7 +59,7 @@
                   actions: [{ action: "", title: "Foo" }]
               }).then(unreached_fulfillment(test)).catch(function(error) {
                   assert_equals(error.name, 'TypeError');
-                  assert_equals(error.message, 'NotificationAction action must not be empty.');
+                  assert_equals(error.message, "Failed to execute 'showNotification' on 'ServiceWorkerRegistration': NotificationAction `action` must not be empty.");
                   test.done();
               });
           }).catch(unreached_rejection(test));
@@ -76,7 +76,7 @@
                   actions: [{ action: "foo", title: "" }]
               }).then(unreached_fulfillment(test)).catch(function(error) {
                   assert_equals(error.name, 'TypeError');
-                  assert_equals(error.message, 'NotificationAction title must not be empty.');
+                  assert_equals(error.message, "Failed to execute 'showNotification' on 'ServiceWorkerRegistration': NotificationAction `title` must not be empty.");
                   test.done();
               });
           }).catch(unreached_rejection(test));