Dart is part of Ads, not Chrome. Chrome didn't want them, while Ads Frontend is heavily dependent upon them.
Aside from Google+ (which was pushed directly by Larry and grudgingly integrated-with by the rest of the company), Google hasn't really had plans "as a company" since the mid-2000s. Big companies (other than Apple under Steve Jobs) don't actually work like that; once you've got a product-focused org chart and strong executives that push their own focus areas, you will necessarily get product-focused initiative that respond to resource availability & market opportunity. The executives are not doing their jobs otherwise.
Aside from Google+ (which was pushed directly by Larry and grudgingly integrated-with by the rest of the company), Google hasn't really had plans "as a company" since the mid-2000s. Big companies (other than Apple under Steve Jobs) don't actually work like that; once you've got a product-focused org chart and strong executives that push their own focus areas, you will necessarily get product-focused initiative that respond to resource availability & market opportunity. The executives are not doing their jobs otherwise.