In Waterfox 56.0.1, the toolbar button is unlabeled; otherwise, everything appears to be functioning normally. <img width="120" alt="waterfox" src="https://user-images.githubusercontent.com/1231218/34374769-b26ba382-ea97-11e7-8796-467c3c667b30.png">
In Waterfox 56.0.1, the toolbar button is unlabeled; otherwise, everything appears to be functioning normally.