Adding a new ChangeLogger class to handle UMA logging of bitrates

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 5c1e37b5b0c2f493c067067369ab0c2a60038618..53c5f96538690d77d7120911e2047cf9fc4813b4 100644
--- a/webrtc/modules/audio_coding/main/acm2/codec_owner.cc
+++ b/webrtc/modules/audio_coding/main/acm2/codec_owner.cc
@@ -21,8 +21,7 @@
 #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"
+#include "webrtc/modules/audio_coding/main/acm2/delayed_logger.h"
 
 namespace webrtc {
 namespace acm2 {
@@ -77,8 +76,10 @@ bool IsG722(const CodecInst& codec) {
 }
 }  // namespace
 
-CodecOwner::CodecOwner()
-    : isac_is_encoder_(false), external_speech_encoder_(nullptr) {
+CodecOwner::CodecOwner(DelayedLogger* bitrate_logger)
+    : isac_is_encoder_(false),
+      external_speech_encoder_(nullptr),
+      bitrate_logger_(bitrate_logger) {
 }
 
 CodecOwner::~CodecOwner() = default;
@@ -182,8 +183,9 @@ void CodecOwner::SetEncoders(const CodecInst& speech_inst,
                       &isac_is_encoder_);
   external_speech_encoder_ = nullptr;
   ChangeCngAndRed(cng_payload_type, vad_mode, red_payload_type);
-  RTC_HISTOGRAM_COUNTS_100(HISTOGRAM_NAME_AUDIO_TARGET_BITRATE_IN_KBPS,
-                           SpeechEncoder()->GetTargetBitrate() / 1000);
+  if (bitrate_logger_) {
+    bitrate_logger_->SetValue(SpeechEncoder()->GetTargetBitrate() / 1000);
+  }
 }
 
 void CodecOwner::SetEncoders(AudioEncoderMutable* external_speech_encoder,
@@ -194,8 +196,9 @@ void CodecOwner::SetEncoders(AudioEncoderMutable* external_speech_encoder,
   speech_encoder_.reset();
   isac_is_encoder_ = false;
   ChangeCngAndRed(cng_payload_type, vad_mode, red_payload_type);
-  RTC_HISTOGRAM_COUNTS_100(HISTOGRAM_NAME_AUDIO_TARGET_BITRATE_IN_KBPS,
-                           SpeechEncoder()->GetTargetBitrate() / 1000);
+  if (bitrate_logger_) {
+    bitrate_logger_->SetValue(SpeechEncoder()->GetTargetBitrate() / 1000);
+  }
 }
 
 void CodecOwner::ChangeCngAndRed(int cng_payload_type,