UserAgent: Mozilla/5.0 (X11; CrOS armv7l 8530.62.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.70 Safari/537.36
Platform: Platform 8530.62.0 (Official Build) beta-channel veyron_minnie

Steps to reproduce the problem:
1. Install FB Messenger, and enable chat head.
2. Open chat head and try and type a message
3. click on send (try to anyway)

What is the expected behavior?
Clicking the send icon in the chat head should send the message.

What went wrong?
You can't actually click the send icon. Instead the shelf is clicked, opening the system tray. It is as though the chat head becomes transparent at the point where it overlays the shelf.

The only solution is to autohide the shelf. You can't do this with the chat head open, since right clicks do not pass through.

Did this work before? No 

Chrome version: 53.0.2785.70  Channel: beta
OS Version: 8530.62.0
Flash Version: Shockwave Flash 22.0 r0

This is part 1 - I have created a separate issue for OneNote badge, as the behaviour is completely different