You might be referring to Flutter, which is a project of Chrome, started independently from Dart, and who's purpose is to make the core of Chrome better for app

You might be referring to Flutter, which is a project of Chrome, started independently from Dart, and who's purpose is to make the core of Chrome better for app development, not find a purpose for Dart. Flutter started with JS as the scripting language. The Dart team is certainly lending a lot of support to Flutter, because of the promise of a compelling mobile story for Dart.