Moved creation of AudioDecoderFactory to inside PeerConnectionFactory.

webrtc/audio/audio_receive_stream.cc

Index: webrtc/audio/audio_receive_stream.cc
diff --git a/webrtc/audio/audio_receive_stream.cc b/webrtc/audio/audio_receive_stream.cc
index fb17fccefce638c9ad58f894c2c39b88254acef9..2a7fc62c77f847c8967ca36994c0bea46acf9767 100644
--- a/webrtc/audio/audio_receive_stream.cc
+++ b/webrtc/audio/audio_receive_stream.cc
@@ -94,6 +94,14 @@ AudioReceiveStream::AudioReceiveStream(
   channel_proxy_ = voe_impl->GetChannelProxy(config_.voe_channel_id);
   channel_proxy_->SetLocalSSRC(config.rtp.local_ssrc);
 
+  // This is where we'd like to set the decoder factory to use. However, since
+  // it needs to be included when constructing Channel, we cannot do that until
+  // we're able to move Channel ownership into the Audio{Send,Receive}Streams.
+  // The best we can do is check that we're not trying to use two different
+  // factories using the different interfaces.
+  RTC_CHECK(config.decoder_factory);
+  RTC_CHECK(config.decoder_factory == channel_proxy_->GetAudioDecoderFactory());
+
   channel_proxy_->RegisterExternalTransport(config.rtcp_send_transport);
 
   for (const auto& extension : config.rtp.extensions) {