This happens since when we close the main browser window, the bookmark bubble is closed via Widget::CloseNow, where we don't orderOut/hide the window first before closing it. So when the compositor is destroyed while closing the window, it seems the window shadow is not invalidated. Explicitly calling [window_ invalidateShadow] after DestroyCompositor in ~BridgedNativeWidget() doesn't seem to help.

Note this is also the case for dialogs other than the bookmark bubble - collected cookies, http auth dialog etc.

I can't repro this, even when stepping through frame-by-frame. Also checked persistent bubbles.

I thought r426407 may have influenced this but I checked back to r412413 (54.0.2831.0 Aug 17 2016). This was possibly an AppKit bug.

Haven't tried on a retina screen, but I'm pretty sure this is WontFix.

Actually I can repro this with Cmd+w and permissions bubbles in Canary, so there's definitely something to address here.

I can't repro this. tapted, can you still repro it?

I can still repro.

macOS 10.12.13
Chrome 59.0.3069.0 

1. Have two browser tabs
2. Open https://permission.site/ in the second tab
3. Click Notifications/Location/something to get a permission bubble
4. Press Cmd+w

tapted: this doesn't repro for me with the steps from #7 - I don't see the shadow after step 4. Did this get fixed in some way that isn't marked on this bug?

Oh man. Yeah I can not repro in 63.0.3230.0 or Version 63.0.3218.0 in 10.12.6.  (I said 10.12.13 earlier.. which doesn't exist - maybe I meant 10.12.3).

It's possible r500189 influenced this, but I can not repro with --ui-disable-zero-copy either. There is also r487421, but that's also unlikely.

I suspect this is an AppKit bug that was fixed.

Let's put this to bed for now.