I think other folks covered this one, but yeah the difference here is that this expanded notification API is for Chrome apps, much like Mozilla has non-standards track APIs that are targeting Firefox OS apps.
Chrome supports the W3C standard Notifications API: http://caniuse.com/#feat=notifications as well as edits the spec for it: https://dvcs.w3.org/hg/notifications/raw-file/tip/Overview.h... This works today in Chrome, Firefox, Opera.
The permission model on packaged apps is completely different, and allows for APIs that have a lot more power (raw USB, TCP access) and as such, it's hard to find a way to expose them to the open web without permission bar overload. :/ I'd personally love to find a way to bring some of the powerful APIs that browsers are developing and exposing them to the web, but it seems like we're not there yet.
For Dart.. think of it as another compile-to-JS language that was designed for large app authoring & maintenance productivity. Its performance as compiled JS seems to be pretty good already so you can target all modern browsers with Dart apps already.
But, ultimately, I'm an open web kind of guy. My money's on APIs that the web shares and I see compatibility across the web as the characteristic that drives its power and reach. Chrome's working on a lot of APIs for the open web platform (see my links above) and is constantly working with other browser vendors to get feedback, buy-in, and identify the best APIs that the web can share.
The permission model on packaged apps is completely different, and allows for APIs that have a lot more power (raw USB, TCP access) and as such, it's hard to find a way to expose them to the open web without permission bar overload. :/ I'd personally love to find a way to bring some of the powerful APIs that browsers are developing and exposing them to the web, but it seems like we're not there yet.
For Dart.. think of it as another compile-to-JS language that was designed for large app authoring & maintenance productivity. Its performance as compiled JS seems to be pretty good already so you can target all modern browsers with Dart apps already.
But, ultimately, I'm an open web kind of guy. My money's on APIs that the web shares and I see compatibility across the web as the characteristic that drives its power and reach. Chrome's working on a lot of APIs for the open web platform (see my links above) and is constantly working with other browser vendors to get feedback, buy-in, and identify the best APIs that the web can share.