GitLab

This adds a new BufferUsage of PROTECTED_VDA_WRITE which is intended to
be used by HW video decoders to decode to a HW protected buffer.
Initially this will only target the VAAPI decoders.

This path will not be used yet, as there are other CLs pending to
enable protected decode in VAAPI as well as kernel patches for the
graphics driver. The high level functionality is also behind a Chrome
flag.

BUG=b:153111783
TEST=Built/ran with full prototype

Change-Id: I775bda3782e5c72b28cbbf2c6c4b0e0eed76abaa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2499087Reviewed-by: ccameron <ccameron@chromium.org>
Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Commit-Queue: Jeffrey Kardatzke <jkardatzke@google.com>
Cr-Commit-Position: refs/heads/master@{#825978}