Add CVO support to video_coding layer.

CVO is, instead of rotating frame on the capture side, to have renderer rotate the frame based on a new rtp header extension.

The change includes
1. encoder side needs to pass this from raw frame to the encoded frame.
2. decoder needs to copy it from rtp packet (only the last packet of a frame has this info) to decoded frame.

R=mflodman@webrtc.org
TBR=stefan@webrtc.org

BUG=4145

Review URL: https://webrtc-codereview.appspot.com/46429006

Cr-Commit-Position: refs/heads/master@{#8767}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8767 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/video_coding/main/source/frame_buffer.cc

@@ -13,6 +13,7 @@
 #include <assert.h>
 #include <string.h>
 
+#include "webrtc/base/checks.h"
 #include "webrtc/modules/video_coding/main/source/packet.h"
 #include "webrtc/system_wrappers/interface/logging.h"
 
@@ -146,6 +147,18 @@ VCMFrameBuffer::InsertPacket(const VCMPacket& packet,
 
     _latestPacketTimeMs = timeInMs;
 
+    // http://www.etsi.org/deliver/etsi_ts/126100_126199/126114/12.07.00_60/
+    // ts_126114v120700p.pdf Section 7.4.5.
+    // The MTSI client shall add the payload bytes as defined in this clause
+    // onto the last RTP packet in each group of packets which make up a key
+    // frame (I-frame or IDR frame in H.264 (AVC), or an IRAP picture in H.265
+    // (HEVC)).
+    if (packet.markerBit) {
+      DCHECK(!_rotation_set);
+      _rotation = packet.codecSpecificHeader.rotation;
+      _rotation_set = true;
+    }
+
     if (_sessionInfo.complete()) {
       SetState(kStateComplete);
       return kCompleteSession;