Accounts.onCreateUser(function(options, user) {
  if (options.profile) {
    options.profile.picture = 'http://graph.facebook.com/' + user.services.facebook.id + '/picture/?type=large';
    user.profile = options.profile;
  }
  return user;
});
Accounts.onCreateUser(function(options, user) {
  if(options.profile) {
    options.profile.picture = 'http://graph.facebook.com/' + user.services.facebook.id + '/picture/?type=large';
    user.profile = options.profile;
    user.username = user.profile.name;
  }
  return user;
});

Save name as user profile.