Mozilla has been resisting Googles libre codecs even though they come with full source code and a patent pledge. Google has already even paid to eliminate

Mozilla has been resisting Googles libre codecs even though they come with full source code and a patent pledge. Google has already even paid to eliminate potential threat from the evil MPEG LA. It is as free(libre) as you can get in this space. Source? As far as I can tell Firefox implements WebM for <video> and VP8 for WebRTC. In what way is Firefox resisting Google's libre codecs?