Sending JS errors to server

gistfile1.js

window.onerror = function(message, url, line_num) {

  // Standard error information
  var error = '\n JS Error: ' + message + ' from ' + url + ':' + line_num;
  error += '\n URL: ' + document.URL;
  
  // User agent info, using https://github.com/caseyohara/user-agent
  var user_agent = new UserAgent();
  error += '\n Browser: ' + user_agent.browser_name + ' ' + user_agent.browser_version + ' | OS: ' + user_agent.os + ' | Platform: ' + user_agent.platform;

  // User information - I find it useful to know who's logged in, so I can contact them for more info. Modify for your own use.
  if (USER_INFO) error += '\n User: ' + USER_INFO.email + ' http://' + window.location.host + '/user/' + USER_INFO.id; 

  // Send it using my standard AJAX wrapper function, POSTING to a view that calls logging.error() on the error= arg
  sendData('log-error', 'error=' + error, function() {});

  return false;
};

Does it work on WebKit browsers these days?