UserAgent: Mozilla/5.0 (X11; CrOS x86_64 8172.60.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36
Platform: 8172.60.0 (Official Build) stable-channel auron_paine

Example URL:
https://play.google.com/music/listen

Steps to reproduce the problem:
1. connect via bluetooth headset which have a next / previous buttons (i'm using sony sbh-50)
2. play one of your google music playlists
3. try to switch to the next song with the next button on the bluetooth headset
4. nothing happens

What is the expected behavior?
It should switch to the next song.

What went wrong?
It simply does nothing.

Did this work before? N/A 

Is it a problem with Flash or HTML5? N/A

Does this work in other browsers? Yes 

Chrome version: 51.0.2704.103  Channel: stable
OS Version: 8172.60.0
Flash Version: Shockwave Flash 22.0 r0

I'm using this headset on windows 10 with chrome 51, too. And it works with google play music. So it must be an chrome os issue.