third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/onactivate-throw-error-then-prevent-default-worker.js

// Ensure we can handle multiple error handlers. One error handler
// calling preventDefault should cause the event to be treated as
// handled.
self.addEventListener('error', function(event) {});
self.addEventListener('error', function(event) { event.preventDefault(); });
self.addEventListener('error', function(event) {});
self.addEventListener('activate', function(event) { throw new Error(); });