GitLab

Switched D3D11VideoDecoder to use VideoFrame::ReleaseMailboxCB.

Also added some random small cleanups (error checking, mostly).

Bug: 
Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: Ia4492de5c2506678bcdabc16de4c19dde92e4186
Reviewed-on: https://chromium-review.googlesource.com/847679
Commit-Queue: Frank Liberato <liberato@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526808}