I think Google put lot of marketing budget for Dart. But I don't see it ever comes in discussion regarding popularity or lack of it.
It is fine a lot of people do not like Go but claiming its popular just because of Google seems baseless.
It is fair to say that without those names attached I would have likely passed it by. Google is boring, but those three names, for me at least, I had to take a look.
Let's see if Flutter and Fuschia teams manage to push adoption for Dart.
> Google & adoption
I think it helped get around the initial cycle of drawing in the curious. An argument counter to claims regarding the importance of the people involved would point out Plan9 etc. that are hardly widely known, much less adopted.
In sum, I think the role of Google in one becoming a Go programmer depends entirely on when it happened. Today, of course Go has its own brand name. 8 years ago, it was Google that eased the debutante phase of the language.