Hmmm... I loaded this page as a test – I'm using version 23 of Chrome – and the text is being formatted correctly. Not in Courier, mind you, but in Menlo (which is effectively a revamped version of Monaco).
You may want to check Chrome's font settings – paste chrome://chrome/settings/fonts#font into the address bar – and see what it has decided to use as its fixed-width font. Curiously, in my case it seems to think that it should be using Courier, but (as I mentioned earlier) it actually uses Menlo instead.
