UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36

Steps to reproduce the problem:
1. Go to (e.g.) https://play.google.com/music/listen in a network with a Chromecast
2. Check that "Cast..." is available in the "Hamburger" menu (between "Print..." and "Find...")
3. Add Play Music to desktop "Hamburger" > "More Tools" > "Add to destkop...", and check "Open as window".
4. Run the just created "app", "Hamburger" menu is unavailable
5. The "application" menu (on left of the window title bar) has several items from the "Hambuger" menu, including "Print..." and "Find..." but not "Cast..."

What is the expected behavior?
I'd expect "Cast..." to be available, because it is required by certain websites, including Google Play Music.

What went wrong?
Can't cast Google Play Music to my Chromecast from the Desktop shortcut I created.

Did this work before? Yes It used to work with the Google Chromecast extension

Chrome version: 52.0.2743.116  Channel: stable
OS Version: 10.0
Flash Version: Shockwave Flash 22.0 r0

Google Play Music used to have a button for this in its controls (somewhat like Youtube).

However, it doesn't make much sense for Chrome to demand this of apps, since this is relatively simple to add to the application menu, and consistent with other menu items like print, find, zoom, etc.