Comment 3 for bug 1417319

Unsurprisingly, the first commit that broke this is the one where I relocated all the theme files:

commit 89e4609b3e6c671637ca7bc601ab445d9cc75af2
Author: Aaron Wells <email address hidden>
Date: Wed Oct 22 16:32:03 2014 +1300

    Bug 1383995: Move plugin files into the /theme directory

    Theme files for plugins can now live under the plugin's directory or under
    the theme's directory. Moving the files for the core plugins to /theme
    should make life easier for theme developers by putting them all in one place.

    Change-Id: Icff863c46c80ed2d6be07cd49404bc0b7f5fc4c0