/**
 * MediaKeys namespace.
 */
if (typeof MediaKeys == "undefined") var MediaKeys = {};

MediaKeys.playButton = "//sj-icon-button[@data-id='play-pause']";
MediaKeys.pauseButton = "//sj-icon-button[@data-id='play-pause']";
MediaKeys.skipButton = "//sj-icon-button[@data-id='forward']";
MediaKeys.previousButton = "//sj-icon-button[@data-id='rewind']";

/**
 * MediaKeys namespace.
 */
if (typeof MediaKeys == "undefined") var MediaKeys = {};

MediaKeys.playButton = "//*[@data-id='play-pause'][1]";
MediaKeys.pauseButton = "//*[@data-id='play-pause'][1]";
MediaKeys.skipButton = "//*[@data-id='forward'][1]";
MediaKeys.previousButton = "//*[@data-id='rewind'][1]";

Fix Google Play Music changes in HTML structure