Add picture ID support in RtcVideoEncoder.

Add picture ID support in RtcVideoEncoder.

When Forward Error Correction (FEC) packets arrive, jitter buffer
will consider them missing. The jitter buffer needs to use the
picture ID to see if a new frame is continuous to the previous
frame. Without picture ID, the jitter buffer will not determine
any frame decodable after FEC. Video will hang until the jitter 
buffer drops all packets and requests a key frame.

BUG=347477
TEST=Run apprtc.appspot.com between Linux and CrOS.
Run apprtc.appspot.com loopback on CrOS.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=260269

[wuchengli, 2014-03-28 10:34:22]

PTAL.

I didn't increment |picture_id_| in InitEncode and Encode because they are
called on different threads for now. Putting |picture_id_| in Impl and access it
on the same thread is safer.

[Ami GONE FROM CHROMIUM, 2014-03-28 14:53:20]

lgtm

To unsubscribe from this group and stop receiving emails from it, send an email
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[holmer, 2014-03-28 14:54:53]

On 2014/03/28 14:53:20, Ami Fischman wrote:
> lgtm
> 
> To unsubscribe from this group and stop receiving emails from it, send an
email
> to mailto:chromium-reviews+unsubscribe@chromium.org.

lgtm

[Ami GONE FROM CHROMIUM, 2014-03-28 14:57:15]

lgtm

[wuchengli, 2014-03-28 15:29:13]

The CQ bit was checked by wuchengli@chromium.org

[commit-bot: I haz the power, 2014-03-28 15:34:00]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wuchengli@chromium.org/216793002/40001

[commit-bot: I haz the power, 2014-03-28 17:07:00]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-28 17:07:01]

Try jobs failed on following builders:
  tryserver.chromium on mac_chromium_rel

[Ami GONE FROM CHROMIUM, 2014-03-28 17:11:15]

The CQ bit was checked by fischman@chromium.org

[commit-bot: I haz the power, 2014-03-28 17:13:35]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wuchengli@chromium.org/216793002/40001

[commit-bot: I haz the power, 2014-03-28 19:04:05]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-28 19:04:05]

Try jobs failed on following builders:
  tryserver.chromium on mac_chromium_rel

[Ami GONE FROM CHROMIUM, 2014-03-28 19:16:00]

The CQ bit was checked by fischman@chromium.org

[commit-bot: I haz the power, 2014-03-28 19:20:53]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wuchengli@chromium.org/216793002/40001

[commit-bot: I haz the power, 2014-03-28 20:50:09]

Change committed as 260269