Follow-up to https://bugs.launchpad.net/nuvola-player/+bug/1157376 In WebKitGtk, and possibly on other platforms (I haven't tested), if you view the Google Play Music player, the controls are rendered incorrectly. On forward, play, and back, little grey horizontal lines are rendered. This is expected. However, the lines don't extend to the rest of the bottom bar, which is unexpected. Launchpad summary: When using Google Play Music, I've noticed a glitch around the Google Play Music controls (play, forward, backward): little grey lines appear horizontally. I've attempted to reproduce this in the latest Firefox (19.0.2 from the Ubuntu repositories), and failed. The lines appear at no particular time, but occasionally their disappearance corresponds to the pointer moving outside the window. Also, sometimes they appear when I mouse over one of the controls. Additional debugging information can be found on the Launchpad bug.