src: nw2: fix mac frameless window
src: nw2: fix mac frameless window

https://github.com/nwjs/chromium.src/commit/2828945183ec598b4b45cd443838cd57845d9172

nwjs/nw.js,nwjs/nw.js,nwjs/nw.js,nwjs/nw.js,nwjs/nw.js,nwjs/nw.js