Menu items appears quickly after hiding and black browser area in Chrome on OSX

[kler]

After the items are hidden when the menu is closing, the menu items appears quickly before they are completely invisible as shown in the following screen recording.

Another thing which I am uncertain if it should be reported as a separate bug is that the browser area "flashes" and becomes black for a moment when an animation begins or ends.

I collected these bugs in a screen recording, I hope this gives a better idea on how to reproduce them.
Screen recording contains annotations on what is happening.

http://www.youtube.com/watch?v=N5Ow_bvcAzM