Start NACKing as soon as we have the first packet of a key frame.

BUG=1605

Review URL: https://webrtc-codereview.appspot.com/1307007

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3855 4adac7df-926f-26a2-2b94-8c16560cd09d

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

diff --git a/webrtc/modules/video_coding/main/source/frame_buffer.cc b/webrtc/modules/video_coding/main/source/frame_buffer.cc
index bc1407b..69ef0a2 100644
--- a/webrtc/modules/video_coding/main/source/frame_buffer.cc
+++ b/webrtc/modules/video_coding/main/source/frame_buffer.cc
@@ -217,6 +217,12 @@
 }
 
 bool
+VCMFrameBuffer::HaveFirstPacket() const
+{
+    return _sessionInfo.HaveFirstPacket();
+}
+
+bool
 VCMFrameBuffer::HaveLastPacket() const
 {
     return _sessionInfo.HaveLastPacket();