ref: 1663eff7f8e8e820c6037157fcc9917d8ece9c28
dir: /third_party/libwebm/README.libvpx/
URL: https://chromium.googlesource.com/webm/libwebm Version: 249629d46c6e9391f25a90cff6d19075f47474cb License: BSD License File: LICENSE.txt Description: libwebm is used to handle WebM container I/O.