Merge 268831 "Replicate FFmpeg's video frame allocation strategy."

> Replicate FFmpeg's video frame allocation strategy.
> 
> This should avoid accidental overreads and overwrites due to our
> VideoFrame's not being as large as FFmpeg expects.
> 
> BUG=368980
> TEST=new regression test
> 
> Review URL: https://codereview.chromium.org/270193002

TBR=dalecurtis@chromium.org

Review URL: https://codereview.chromium.org/308733002

git-svn-id: svn://svn.chromium.org/chrome/branches/1916/src@273520 0039d316-1c4b-4281-b951-d872f2087c98
2 files changed