Move Rent-A-Codec out of CodecManager

webrtc/modules/audio_coding/acm2/audio_coding_module_impl.h

Index: webrtc/modules/audio_coding/acm2/audio_coding_module_impl.h
diff --git a/webrtc/modules/audio_coding/acm2/audio_coding_module_impl.h b/webrtc/modules/audio_coding/acm2/audio_coding_module_impl.h
index a624b23067fef11ca4eded8732f2d30267f2bd91..337ff13fb2724a8051487ab19c5274a1b41525db 100644
--- a/webrtc/modules/audio_coding/acm2/audio_coding_module_impl.h
+++ b/webrtc/modules/audio_coding/acm2/audio_coding_module_impl.h
@@ -249,6 +249,7 @@ class AudioCodingModuleImpl final : public AudioCodingModule {
   AcmReceiver receiver_;  // AcmReceiver has it's own internal lock.
   ChangeLogger bitrate_logger_ GUARDED_BY(acm_crit_sect_);
   CodecManager codec_manager_ GUARDED_BY(acm_crit_sect_);
+  RentACodec rent_a_codec_ GUARDED_BY(acm_crit_sect_);
 
   // This is to keep track of CN instances where we can send DTMFs.
   uint8_t previous_pltype_ GUARDED_BY(acm_crit_sect_);