Fix issue 310.

BUG=310
TEST=session_info_unittest.cc

Review URL: https://webrtc-codereview.appspot.com/404004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@1782 4adac7df-926f-26a2-2b94-8c16560cd09d

src/modules/video_coding/main/source/session_info.cc

diff --git a/src/modules/video_coding/main/source/session_info.cc b/src/modules/video_coding/main/source/session_info.cc
index 21b80a0..7261403 100644
--- a/src/modules/video_coding/main/source/session_info.cc
+++ b/src/modules/video_coding/main/source/session_info.cc
@@ -325,6 +325,9 @@
 
 int VCMSessionInfo::MakeDecodable() {
   int return_length = 0;
+  if (packets_.empty()) {
+    return 0;
+  }
   PacketIterator it = packets_.begin();
   // Make sure we remove the first NAL unit if it's not decodable.
   if ((*it).completeNALU == kNaluIncomplete ||