Moved Opus-specific payload splitting into AudioDecoderOpus.

webrtc/modules/audio_coding/neteq/packet_buffer.cc

Index: webrtc/modules/audio_coding/neteq/packet_buffer.cc
diff --git a/webrtc/modules/audio_coding/neteq/packet_buffer.cc b/webrtc/modules/audio_coding/neteq/packet_buffer.cc
index c5b23dce068c3df75b816579b2964500fd828b7d..84f272c4f6d0939852f2a379c7df18f68778aa96 100644
--- a/webrtc/modules/audio_coding/neteq/packet_buffer.cc
+++ b/webrtc/modules/audio_coding/neteq/packet_buffer.cc
@@ -281,7 +281,9 @@ size_t PacketBuffer::NumSamplesInBuffer(size_t last_decoded_length) const {
   size_t last_duration = last_decoded_length;
   for (Packet* packet : buffer_) {
     if (packet->frame) {
-      if (!packet->primary) {
+      // TODO(hlundin): Verify that it's fine to count all packets and remove
+      // this check.
+      if (packet->priority != Packet::Priority(0, 0)) {
         continue;
       }
       size_t duration = packet->frame->Duration();