media/gpu/test: Adapt new video decode accelerator tests to use import mode.

The media::VideoDecoder interface doesn't have an allocate mode, video frames
are allocated inside a buffer allocator. To prepare for the migration of the
video decoders to the media::VideoDecoder interface, the video player has been
adapted to use import mode.

This CL also improves the way video frames are consumed. Rather than providing
a callback, the video frame is wrapped in another video frame that will release
the associated picture buffer upon destruction. This is done to prepare for the
integration of the frame validator, so multiple entities will be able to consume
video frames.

TEST=ran new VDA tests on nocturne

BUG=879065

Change-Id: I88d1f2c44489ed1692246372e6bd872efae5205b
Reviewed-on: https://chromium-review.googlesource.com/c/1399761
Commit-Queue: David Staessens <dstaessens@chromium.org>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#621905}
11 files changed