title: Taking screenshots of a page while its loading using Selenium WebDrivers
body: <p>I have started using Selenium WebDrivers to automate some performance testing. I found out that we could take screenshots of a page after the page has completed loading using WebDrivers: <a href="http://seleniumhq.org/docs/04_webdriver_advanced.html#taking-a-screenshot" rel="nofollow">http://seleniumhq.org/docs/04_webdriver_advanced.html#taking-a-screenshot</a>. However, I want to be able to take screenshots while the page is loading to analyze its loading time and pattern, much like what webpagetest does (http://www.webpagetest.org/). Is there an API that I could use to accomplish this task using WebDrivers?</p>
  
  <p>I am using the FirefoxWebDriver and the Java client for the same. I appreciate help or tips.</p>
  
  <p>Thanks!</p>