How to set keymap to close the VCS difference window in OS X

I want to set RubyMine/IntelliJ to close the "compare with latest repo version" window on OSX.

You guys should really think your OSX keystrokes, but that's your call I guess.

In OS X the standard would be to close editor tabs and pop up windows via cmd-w.  You guys don't follow that convention so I've re-mapped most things to work that way.

The one I haven't been able to get right is close the VCS "compare with latest repo version" pop up window.  ESC works, but I can't figure out how to make cmd-w to work.  Any hints?

thanks