Reading the upstream bug more carefully, it's a bug in Metacity. Re- assigning.
** Package changed: chromium-browser (Ubuntu) => metacity (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/710125 Title: Chromium leaves trails when compositing is turned on -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs