Threaded compositing for producing iOS-like scrolling?

Question

What is threaded compositing?

It was referred to in a recent Paul Irish Post as a means to produce iOS-like scrolling:

I searched chrome about:flags but wasn't able to find what Paul was referring to. I assume it has something to do with how elements are rendered but I'm interested in if/how compositing can be tackled programmatically (in JavaScript?).

Answer 1

At this point, threaded compositing is an experimental feature, and thus is only available in the dev or canary channel. If you'd like to try this feature out, you can download a Chrome build in the dev or canary channel.

About the feature itself, it is described as follows on chrome://flags/:

Uses a secondary thread to perform web page compositing. This allows smooth scrolling, even when the main thread is unresponsive.

Answer 2

Tested this flag on this page, still scrolling freezes http://romaxa.info/tests/scrolltest/layout3_busy_long.html

Works good on XUL firefox (Mobile version with multiprocess layers)