Chrome 57 released yesterday, not quite a week ahead of schedule, with Grid support enabled. So that’s two browsers with Grid support in the space of two days, including the most popular browser in the world right now. Safari has it enabled in Technology Preview builds, and just blogged an introduction to Grid, so it definitely feels like it’ll be landing there soon as well. No word from Edge, so far as I know.
I did discover a Chrome bug in Grid this morning, albeit one that might be fairly rare. I filed a bug report, but the upshot is this: most or all of an affected page is rendered, and then gets blanked. I ran into a similar bug earlier this year, and it seemed to affect people semi-randomly—others with the same OS as me didn’t see it, and others with different OSes did see it. This leads me to suspect it’s related to graphics cards, but I have no proof of that at all. If you can reproduce the bug, and more importantly come up with a reliable way to fix it, please comment on the Chromium bug!