I was starting to work on this and suddenly *stopped* being able to repro it in either a local build or Canary. I'm going to sit on it until I or someone else sees it again in case another change vanished it.

I'm still seeing this in Canary 73.0.3660.0.

It's hard to get this to happen. I wonder if there's a race somewhere. Once it starts happening, it stays consistently happening.

I can repro this pretty consistently by using Cmd-C/Cmd-V/Cmd-X keyboard shortcuts in Gmail. When I use one of them, the Edit menu stays highlighted until I actually click on it.

Follow up: I have a consistent repro for this now. It's the same as Issue 920795: when I plug my laptop into an external monitor, I trigger this bug and Issue 920795. Before I plug into the monitor, the menu behaves correctly and the top toolbar correctly animates in when mousing to the top in fullscreen.

After I plug in my monitor, the menu stays highlighted when I use Ctrl-C/etc., and the fullscreen toolbar doesn't animate in any more.