Leveraged multi-core rendering for libVPX (VP8/VP9 WebM decoding).
I watch a fair amount of Youtube videos these days, and had *just* purchased a 4k TV for my primary computer display one month before Youtube decided to stop encoding 4k videos in h.264.
It was amazing watching the back catalog of 4k videos from some of my favorite channels... only to have the beauty snatched away on their newer videos.
Youtube still has 4k videos in webm (vp9), but until recently my poor computer didn't have the grunt to render more than a second or two of a 4k VP9 video before dropping the next 10 seconds worth of frames.
However tonight, as of trying out 27.4.0a1 (2017-05-02 build) on the unstable channel I once again can smoothly render 4k Youtube videos!
To everyone who has been working on the video improvements since v26, Thank You.