 An important feature of model or pop-up components is that they are easy to close. With a consistent mechanism for doing so, those mechanisms are called close requests. They are typically the escape key on desktop platforms and the back gesture or button on Android. Web developers had no good way to handle close requests for their own components. This is especially problematic on Android devices. We're providing the simple closing behavior for the back gesture was quite complex. This conversion brings the solution with close watcher and new API for directly listening and responding to close requests. You can see an example on the screen. It also includes upgrades to dialogue and pop-over to use the new close request framework so that they respond to the Android back button.