use_system_ffmpeg broken in gentoo.

use_system_ffmpeg broken on gentoo side.

because if use "system" ffmpeg, AVFrame has no member named "owner".

we need use #ifdef to use the single codec context, if system ffmpeg is used.

but what if "system" is ffmpeg-mt?

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=53695

[jiesun, 2010-07-26 21:27:23]

please have a look.

[Alpha Left Google, 2010-07-26 21:32:02]

ideally you can build those files and enable those features only if
use_system_ffmpeg is not used. I think we can disable all those buffer rotation
feature when system provides the ffmpeg since we don't know the version and the
internal of ffmpeg.

[Alpha Left Google, 2010-07-26 21:34:31]

LGTM.