Play/Pause/Prev/Fwd buttons not working

What I have: macOS 10.10.2(Yosemite) on an iMac mid-2011 + original wireless keyboard.

Suddenly, buttons for controlling iTunes (they are located on F7, F8 and F9 buttons) stopped working. Meanwhile, other buttons (volume, brightness, launchpad, etc.) still work.

The keys work in other applications but not with iTunes.

Where should I look to fix this? Notice, the issue happened before updating to OS X Yosemite.

I found this to solve the problem for me, thanks to Major Hayden!

...check your keyboard shortcuts in Chrome:

• Choose Preferences in the Chrome menu in the menu bar
• Click Extensions in the left sidebar
• Scroll all the way to the bottom of the page
• Click Keyboard Shortcuts
• Look at the key bindings in the Google Play Music section
• Remove them all by by pressing the 'X' icon next to them.