Enable injection of a custom NetEqFactory into PeerConnectionFactory.

Injecting both a custom NetEqFactory and an AudioDecoderFactory is not
supported, in that case the AudioDecoderFactory should be wrapped inside
the NetEqFactory.

Bug: webrtc:11005
Change-Id: I4e311eb1bfa03c91bca587d70540e81829f881c9
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158720
Commit-Queue: Ivo Creusen <ivoc@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29673}
diff --git a/modules/audio_coding/include/audio_coding_module.h b/modules/audio_coding/include/audio_coding_module.h
index 05d9380..d8c9260 100644
--- a/modules/audio_coding/include/audio_coding_module.h
+++ b/modules/audio_coding/include/audio_coding_module.h
@@ -21,6 +21,7 @@
 #include "api/audio_codecs/audio_encoder.h"
 #include "api/function_view.h"
 #include "api/neteq/neteq.h"
+#include "api/neteq/neteq_factory.h"
 #include "modules/audio_coding/include/audio_coding_module_typedefs.h"
 #include "system_wrappers/include/clock.h"
 
@@ -68,6 +69,7 @@
     NetEq::Config neteq_config;
     Clock* clock;
     rtc::scoped_refptr<AudioDecoderFactory> decoder_factory;
+    NetEqFactory* neteq_factory = nullptr;
   };
 
   static AudioCodingModule* Create(const Config& config);