You'll still be able to test with Google's servers just not the exact same way. You'll have to use the Mercury Speed Test system.
Here's one that works awesome for me all the time. lh3.googleusercontent.com Mercury Speed Test
Result I just ran on my laptop...
Using that same test on one of my commercial connections I was able to see nearly 600 Mbps, again... confirmed by the client network controller. Google has very fast bandwidth and very quick responding servers, ideal for this test.
You can search the Mercury index for other Google Speed Tests or make your own to nearly any web server you want to test against. Not many people realize that TMN does this. Find one that works good for you and bookmark it. If you like the Google tests, go to the Google Speed Test page, scroll down and click "Custom Index"... then when you visit testmy.net/mercury it will show your favorites. You can custom index by city, state, country or ISP (that the test is hosted on).
Happy Testing!