Adding Opus stereo support to WebRTC

This CL adds support for sending and receiving stereo using the Opus codec.

BUG=issue1013

Review URL: https://webrtc-codereview.appspot.com/930008

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3050 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_coding/neteq/packet_buffer.c b/webrtc/modules/audio_coding/neteq/packet_buffer.c
index 7fbea58..74a4903 100644
--- a/webrtc/modules/audio_coding/neteq/packet_buffer.c
+++ b/webrtc/modules/audio_coding/neteq/packet_buffer.c
@@ -578,7 +578,8 @@
             codecBytes = 1560; /* 240ms @ 52kbps (30ms frames) */
             codecBuffers = 8;
         }
-        else if (codecID[i] == kDecoderOpus)
+        else if ((codecID[i] == kDecoderOpus)  ||
+            (codecID[i] == kDecoderOpus_2ch))
         {
             codecBytes = 15300; /* 240ms @ 510kbps (60ms frames) */
             codecBuffers = 30;  /* Replicating the value for PCMu/a */