I'm pretty sure the Google Play Music web app can respond to media keys, at least in Chrome. Here's someone describing how to disable it: http://www.omgchrome

I'm pretty sure the Google Play Music web app can respond to media keys, at least in Chrome. Here's someone describing how to disable it: http://www.omgchrome.com/chrome-google-music-media-keys/ http://www.omgchrome.com/chrome-google-music-media-keys/