. My ubuntu 14.04.3 came shipped with libcairo2 package version 1.13.0~20140204-0ubuntu1.1 which dates back to ~2013/2014 according to http://cairographics.org/news/.
I guess that Firefox 40.0.3 still comes shipped with the old Cairo 1.9.5. Basically that means that the problem eventually is solved as soon as firefox updates to Cairo 1.13.0+.
Cairo 1.9.5 dates back to ~2009/2010 according to http:// cairographics. org/news/.
. My ubuntu 14.04.3 came shipped with libcairo2 package version 1.13.0~ 20140204- 0ubuntu1. 1 which dates back to ~2013/2014 according to http:// cairographics. org/news/.
I guess that Firefox 40.0.3 still comes shipped with the old Cairo 1.9.5. Basically that means that the problem eventually is solved as soon as firefox updates to Cairo 1.13.0+.