Update FFmpegDemuxer unknown duration logic to work for video-only streams.

Update FFmpegDemuxer unknown duration logic to work for video-only streams.

The FFmpegDemuxer would only compute the duration at the end of
playback for clips without a duration that contained audio. This was not
being done for video-only streams which resulted inconsistent behavior.
This change simply make the duration computation logic apply to all
stream types.

TEST=FFmpegDemuxerTest.Read_EndOfStream_NoDuration_VideoOnly, FFmpegDemuxerTest.Read_EndOfStream_NoDuration_AudioOnly

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=243304

[xhwang, 2014-01-04 01:12:38]

lgtm % a tiny nit

https://codereview.chromium.org/105503011/diff/1/media/filters/ffmpeg_demuxer.cc
File media/filters/ffmpeg_demuxer.cc (right):

https://codereview.chromium.org/105503011/diff/1/media/filters/ffmpeg_demuxer...
media/filters/ffmpeg_demuxer.cc:804: if (duration != kNoTimestamp() && duration
> max_duration)
nit: the check duration != kNoTimestamp() seems redundant?

[acolwell GONE FROM CHROMIUM, 2014-01-04 02:39:26]

On 2014/01/04 01:12:38, xhwang wrote:
> lgtm % a tiny nit
> 
>
https://codereview.chromium.org/105503011/diff/1/media/filters/ffmpeg_demuxer.cc
> File media/filters/ffmpeg_demuxer.cc (right):
> 
>
https://codereview.chromium.org/105503011/diff/1/media/filters/ffmpeg_demuxer...
> media/filters/ffmpeg_demuxer.cc:804: if (duration != kNoTimestamp() &&
duration
> > max_duration)
> nit: the check duration != kNoTimestamp() seems redundant?
While removing it would work, I didn't think in general we are supposed to make
assumptions about the actual value of kNoTimestamp(). That is why I always check
for it explicitly.

[xhwang, 2014-01-07 01:23:29]

lgtm++

[commit-bot: I haz the power, 2014-01-07 09:51:07]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/acolwell@chromium.org/105503011/1

[commit-bot: I haz the power, 2014-01-07 15:28:50]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/acolwell@chromium.org/105503011/1

[commit-bot: I haz the power, 2014-01-07 16:15:09]

Change committed as 243304