Revert of Remove accelerated hardware decode blacklist entry for Mac OS X. (patchset #2 id:20001 of https://codereview.chromium.org/849143002/)

Reason for revert:
This seems related to the regression here:
https://build.chromium.org/p/chromium.gpu/builders/Mac%20Release%20%28Intel%29/builds/45738

Original issue's description:
> Remove accelerated hardware decode blacklist entry for Mac OS X.
>
> Now that VTVideoDecodeAccelerator exists, this entry is not necessary.
>
> BUG=133828
>
> Committed: https://crrev.com/c0e69446b02848fce2e311662a43b8e782304ae3
> Cr-Commit-Position: refs/heads/master@{#311622}

TBR=scherkus@chromium.org,sievers@chromium.org,sandersd@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=133828

Review URL: https://codereview.chromium.org/853563003

Cr-Commit-Position: refs/heads/master@{#311659}
2 files changed