VideoDecoderShim has needed several emergency reverts/fixes recently ( bug 835506 , bug 828656 and  bug 804433 , for example), partly caused by the lack of any unit tests for the class. Both  bug 804433  and  bug 835506  have requested that tests be added for this class, or for the Pepper video decode pipeline in general, assuming it will continue to exist once apps are deprecated.

I'm not sure who the right owner for this is, so I'm picking a component based on the OWNERS file.