Wait for page to fully load with webdriverjs

What's the best way to wait for a page to fully load using selenium-webdriver for javascript? I noticed this question is quite similar but I need an implementation in javascript.

var webdriver = require('selenium-webdriver'),
    By = webdriver.By,
    until = webdriver.until;

var driver = new webdriver.Builder()
    .forBrowser('firefox')
    .build();

driver.get('http://www.google.com');

// Wait for the page to fully load here...
// Something like this...
// driver.wait(...);

// Then do other stuff here

driver.quit();