From the article:
Google Ads, one of Dart's biggest customers, is committed to Dart and supports this new strategy. Scott Silver, VP of Engineering for Ads, says, “We are committed to building our next-generation web apps with Dart, and a renewed focus on generating optimal JavaScript helps us deliver great apps to everyone with a modern browser. Dart has significantly improved our engineers' productivity and our ability to quickly launch and iterate. We currently have one million lines of Dart code and the number is growing fast.” Many other teams inside of Google, such as Google Fiber, Google Express, and Google's internal sales team, use Dart for business-critical apps.