GitLab

This allows better integration of OS X and iOS media frameworks
with chromium code and makes buffer management less problematic,
especially when using CVPixelBufferPools provided by hardware
encoders or decoders.

BUG=401308
R=dalecurtis,hubbe

Review URL: https://codereview.chromium.org/446163003

Cr-Commit-Position: refs/heads/master@{#292023}