IMO yes this would be a clear win since rotation lock is a simple "on/off" toggle similar to https://codereview.chromium.org/2907503002/ which is implemented as a toggle-able tile.

This would be the sixth tile added to the tiles row, and it looks like seven icons can fit comfortably. I think it makes sense to make this change now, but note it brings us one step closer to requiring the 'tile mode' implementation specced in issue 677581.

Possible bonus user delight opportunity: consider using a moticon when toggling on/off similar to what is seen in Android system UI.

indeed, rotation lock, nightlight and the message center's do not disturb icons are three candidates on our radar for adding motion.

ping Sebastien, wdyt?

Sebastien, friendly ping. Would you be comfortable with rotation lock being turned into a tile even before the full "tile mode" spec is implemented?

Sorry for the delay. I think rotation lock is a great candidate for a tile.
I think it should be positioned right after the Night Light icon.
Adding Jenn for Sanity check.

Agreed, would be great to move this in to the tile area!

It'd be great for this (similar to Night Light) would be able to have feedback about the state upon tapping since we'll be losing the (arguably not great) strings here by moving it into a tile, and we can't rely on tooltips here to express strings.

One more thing: would be good to prevent accidentally tapping something destructive, so to the left of Night Light might be a more protected location.

I've filed bug 738485 to track that effort and assigned it to myself.
@Jenn feel free to mark it as blocking this bug. If not, let's go ahead and make the change and get the toggle feedback in later. 

Done — would consider this a regression in usability if we didn't have feedback since we do a better job with that today, and it's a more commonly toggled action.

Sounds good I'll get to the new feedback system when I come back.