Stop Re: www?
it's also the protocol
Actually, the protocol part is https://, not www, and it is mandatory, according to the relevant Internet standards (not looking up the exact RFCs, but yes, that's how it is defined). A URL is not compliant without the protocol part.
Of course, Google's proposal will not break URLs comms-wise since they will only hide the protocol part from the user in the interface. By the way, I don't use Chrome, but at least some smartphone browsers do that today. In all cases if you copy/paste the missing parts will be handled. Also, since times immemorial browsers knew to assume the protocol an subdomain and even TLD (.com) parts if the user didn't type them - long before the address bar got merged with search.
Having said that, any "simplification" of the URL shown is a horrible idea. I agree with the suspicion that browsers (certainly Chrome) will go to search rather than to an address if an incomplete URL is typed in, and this is probably a part of the motivation. Not showing it, especially to a non-technical user, is vile though. A housewife will not even pay attention to what is shown there and will not be confused or unduly inconvenienced. Everyone else will, however. Think of QA (and R&D after QA report bugs). They will have to play with all conceivable combinations of what is typed and what is shown to verify that everything works (the same way, in all browsers). Or Support. Among imaginable use cases that will be borked is a Hell Desk operator asking "What website does not work for you? Could you please tell me exactly what is written there?" The possibilities are endless.
Biting the hand that feeds IT
