Audio codec implementations: Take optional codec ID argument

None of the built-in codecs do anything with the ID, but callers will
soon require them to accept it.

Bug: webrtc:8941
Change-Id: I0eb77db82d72c7d34cff639fecb67c1e6ec421bf
Reviewed-on: https://webrtc-review.googlesource.com/58089
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Oskar Sundbom <ossu@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22259}
diff --git a/api/audio_codecs/ilbc/audio_decoder_ilbc.h b/api/audio_codecs/ilbc/audio_decoder_ilbc.h
index f7292d6..c233c4b 100644
--- a/api/audio_codecs/ilbc/audio_decoder_ilbc.h
+++ b/api/audio_codecs/ilbc/audio_decoder_ilbc.h
@@ -14,6 +14,7 @@
 #include <memory>
 #include <vector>
 
+#include "api/audio_codecs/audio_codec_pair_id.h"
 #include "api/audio_codecs/audio_decoder.h"
 #include "api/audio_codecs/audio_format.h"
 #include "api/optional.h"
@@ -28,7 +29,9 @@
   struct Config {};  // Empty---no config values needed!
   static rtc::Optional<Config> SdpToConfig(const SdpAudioFormat& audio_format);
   static void AppendSupportedDecoders(std::vector<AudioCodecSpec>* specs);
-  static std::unique_ptr<AudioDecoder> MakeAudioDecoder(Config config);
+  static std::unique_ptr<AudioDecoder> MakeAudioDecoder(
+      Config config,
+      rtc::Optional<AudioCodecPairId> codec_pair_id = rtc::nullopt);
 };
 
 }  // namespace webrtc