chromium/chrome/test/data/extensions/error_console/browser_action_runtime_error/browser_action.js

// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

chrome.browserAction.onClicked.addListener(function(tab) {
  // This will cause a javascript error, since these are not defined.
  foobar = baz;
});