HW acceleration doesn't work for me in the latest build. I noted that Olivier was going to build with a newer version of libva so I went ahead an installed the latest version, as per this guide: https://github.com/intel/media-driver/wiki/How-to-build-and-use-media-driver%3F. Unfortunately that did not change the behavior, so I still see kVideoDecoderName="VpxVideoDecoder"

snap info --abs-time chromium & vainfo dumps below:

name:      chromium
summary:   Chromium web browser, open-source version of Chrome
publisher: Canonical*
store-url: https://snapcraft.io/chromium
contact:   https://bugs.launchpad.net/ubuntu/+source/chromium-browser/+bugs?field.tag=snap
license:   unset
description: |
  An open-source browser project that aims to build a safer, faster, and more stable way for all
  Internet users to experience the web.
commands:
  - chromium.chromedriver
  - chromium
snap-id:      XKEcBqPM06H1Z7zGOdG5fbICuf8NWK5R
tracking:     latest/candidate/vaapi
refresh-date: 2020-05-17T17:46:48-07:00
channels:
  latest/stable:    81.0.4044.138 2020-05-06T18:11:18Z (1143) 161MB -
  latest/candidate: 81.0.4044.138 2020-05-06T14:20:15Z (1143) 161MB -
  latest/beta:      83.0.4103.56  2020-05-15T02:46:16Z (1155) 163MB -
  latest/edge:      84.0.4143.2   2020-05-13T04:57:20Z (1154) 164MB -
installed:          81.0.4044.138                      (1162) 162MB -

libva info: VA-API version 1.8.0
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/iHD_drv_video.so
libva info: Found init function __vaDriverInit_1_8
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.8 (libva 2.1.0)
vainfo: Driver version: Intel iHD driver for Intel(R) Gen Graphics - 20.2.pre (f403839f)
vainfo: Supported profile and entrypoints
      VAProfileNone                   :	VAEntrypointVideoProc
      VAProfileNone                   :	VAEntrypointStats
      VAProfileMPEG2Simple            :	VAEntrypointVLD
      VAProfileMPEG2Simple            :	VAEntrypointEncSlice
      VAProfileMPEG2Main              :	VAEntrypointVLD
      VAProfileMPEG2Main              :	VAEntrypointEncSlice
      VAProfileH264Main               :	VAEntrypointVLD
      VAProfileH264Main               :	VAEntrypointEncSlice
      VAProfileH264Main               :	VAEntrypointFEI
      VAProfileH264Main               :	VAEntrypointEncSliceLP
      VAProfileH264High               :	VAEntrypointVLD
      VAProfileH264High               :	VAEntrypointEncSlice
      VAProfileH264High               :	VAEntrypointFEI
      VAProfileH264High               :	VAEntrypointEncSliceLP
      VAProfileVC1Simple              :	VAEntrypointVLD
      VAProfileVC1Main                :	VAEntrypointVLD
      VAProfileVC1Advanced            :	VAEntrypointVLD
      VAProfileJPEGBaseline           :	VAEntrypointVLD
      VAProfileJPEGBaseline           :	VAEntrypointEncPicture
      VAProfileH264ConstrainedBaseline:	VAEntrypointVLD
      VAProfileH264ConstrainedBaseline:	VAEntrypointEncSlice
      VAProfileH264ConstrainedBaseline:	VAEntrypointFEI
      VAProfileH264ConstrainedBaseline:	VAEntrypointEncSliceLP
      VAProfileVP8Version0_3          :	VAEntrypointVLD
      VAProfileVP8Version0_3          :	VAEntrypointEncSlice
      VAProfileHEVCMain               :	VAEntrypointVLD
      VAProfileHEVCMain               :	VAEntrypointEncSlice
      VAProfileHEVCMain               :	VAEntrypointFEI
      VAProfileHEVCMain10             :	VAEntrypointVLD
      VAProfileHEVCMain10             :	VAEntrypointEncSlice
      VAProfileVP9Profile0            :	VAEntrypointVLD
      VAProfileVP9Profile2            :	VAEntrypointVLD