Add UMA logging for target audio bitrate

webrtc/modules/audio_coding/main/acm2/codec_owner.cc

Index: webrtc/modules/audio_coding/main/acm2/codec_owner.cc
diff --git a/webrtc/modules/audio_coding/main/acm2/codec_owner.cc b/webrtc/modules/audio_coding/main/acm2/codec_owner.cc
index 4d214be24281e313700fa43aca2efd2b20afa8e5..12dec0ae5085ab81d79a70d312e8328e178183ad 100644
--- a/webrtc/modules/audio_coding/main/acm2/codec_owner.cc
+++ b/webrtc/modules/audio_coding/main/acm2/codec_owner.cc
@@ -21,6 +21,8 @@
 #include "webrtc/modules/audio_coding/codecs/opus/interface/audio_encoder_opus.h"
 #include "webrtc/modules/audio_coding/codecs/pcm16b/include/audio_encoder_pcm16b.h"
 #include "webrtc/modules/audio_coding/codecs/red/audio_encoder_copy_red.h"
+#include "webrtc/modules/audio_coding/main/acm2/acm_common_defs.h"
+#include "webrtc/system_wrappers/interface/metrics.h"
 
 namespace webrtc {
 namespace acm2 {
@@ -178,6 +180,8 @@ void CodecOwner::SetEncoders(const CodecInst& speech_inst,
                              int red_payload_type) {
   CreateSpeechEncoder(speech_inst, &speech_encoder_, &isac_codec_,
                       &isac_is_encoder_);
+  RTC_HISTOGRAM_COUNTS_100(kHistogrameNameAudioTargetBitrateInKbps,
+                           SpeechEncoder()->GetTargetBitrate() / 1000);
   external_speech_encoder_ = nullptr;
   ChangeCngAndRed(cng_payload_type, vad_mode, red_payload_type);
 }
@@ -187,6 +191,8 @@ void CodecOwner::SetEncoders(AudioEncoderMutable* external_speech_encoder,
                              ACMVADMode vad_mode,
                              int red_payload_type) {
   external_speech_encoder_ = external_speech_encoder;
+  RTC_HISTOGRAM_COUNTS_100(kHistogrameNameAudioTargetBitrateInKbps,
+                           SpeechEncoder()->GetTargetBitrate() / 1000);
   speech_encoder_.reset();
   isac_is_encoder_ = false;
   ChangeCngAndRed(cng_payload_type, vad_mode, red_payload_type);