How can we automate running the test?

• The API needs to be run inside a browser. If you want to automate the test, you can create a speed test webpage. This page uses the API and starts the test automatically. You may sends the test result to a web service or do whatever you want with it. To automate visiting the speed test page, you will need a tool. I guess a macro management tool like imacros.net can do the job. It also has a free browser plugin which should be good enough for your purpose.
• Also, a headless browser can do the job too. I recommend using PhantomJS for this purpose. It allows you to run the test from command-line.