I add a question mark because the problem no doubt lies not with KM, but between my ears...
However, I've fiddled with making a KM macro to copy the URL and title of the foremost tab in Chrome, and while the Google Chrome Document URL works fine (as does the older %FrontBrowserURL%) -- ie it gets copied to my clipboard as expected -- the Google Chrome Document Title does not -- a blank space is copied to my clipboard, where I'd have expected the title to be.
Usually when this sort of thing comes up it is a user error – but I'm not seeing anywhere that you went wrong...
My next thought was perhaps you had changed the actual Chrome-based browser attached to the Chrome tokens (you can do that with an expert preference), but you mentioned that the Chrome-URL token was working – and that nixes that possibility.
My next thought is that maybe you were having some issue related to using a global variable. That can sometimes get you into trouble, because its persistent and can seemingly show an anomalous result to a macro when in fact it was never rewritten.
Your approach has taught me a great deal about how best to write and test KM macros.
That said, your solution doesn't work on my box. As happened with my previous macros, the text window in your macro shows the URL correctly, but the browser title (both the Chrome and FrontBrowser tokens) as a blank.