Tiled rendering is a bog-standard approach for GPU-accelerated Web browser compositing since Mobile Safari came out in 2007. I'm surprised their version of Chromium wasn't doing it already (and I know at least some Chromium configurations can, for example on mobile). Seems odd that they'd have to do it themselves.
In fact, it's odd that they'd have to use translate3d at all. Just changing the scroll offset on a native scrolling root should cause the compositor's tiled rendering infrastructure to automatically do the right thing.
In fact, it's odd that they'd have to use translate3d at all. Just changing the scroll offset on a native scrolling root should cause the compositor's tiled rendering infrastructure to automatically do the right thing.