Revert "media/gpu: move common codes from chromeos/ to linux"

This reverts commit a18b493a342962aced2edd13200d72e0dae0e8fc.

Reason for revert: Findit identified that this CL caused a build failure in ASan/LSan builder.
https://ci.chromium.org/p/chromium/builders/ci/Linux%20Chromium%20OS%20ASan%20LSan%20Builder/46431
Probably it's because the bot has neither of use_v4l2_codec or use_vaapi and it hits the assert in media/gpu/linux/BUILD.gn.

Original change's description:
> media/gpu: move common codes from chromeos/ to linux
> 
> This partial reverts commit 692de4cb791a78f55ed626ebed48ace7ed9de66e, because
> Cast uses V4L2 and the refactory breaks Cast build.
> 
> 1. Keep chromeos_video_decoder_factory.* unchanged.
> 2. Move the other files from chromeos to linux as these files can be shared by
> all the linux builds.
> 
> Bug: chromium:972585
> Change-Id: I7782af4a6a3723f8f56aa4bcf3d1e49e43c70d1a
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1681972
> Commit-Queue: Yuchen Liu <yucliu@chromium.org>
> Reviewed-by: Miguel Casas <mcasas@chromium.org>
> Reviewed-by: Dan Sanders <sandersd@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#677522}

TBR=mcasas@chromium.org,sandersd@chromium.org,akahuang@chromium.org,hiroh@chromium.org,acourbot@chromium.org,yucliu@chromium.org,dstaessens@chromium.org,cletnick@google.com

Change-Id: I0a9e526e485fdf5b091cfbd34c6e4d2a6c8e93ca
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:972585
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1702084
Reviewed-by: Makoto Shimazu <shimazu@chromium.org>
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#677578}
35 files changed