Adding a new ChangeLogger class to handle UMA logging of bitrates

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

Index: webrtc/modules/audio_coding/main/acm2/codec_manager.cc
diff --git a/webrtc/modules/audio_coding/main/acm2/codec_manager.cc b/webrtc/modules/audio_coding/main/acm2/codec_manager.cc
index d28dcc6ff5e6d63a2fbba52a7873c4869fce93cf..7ad0e014ce5f4b227d1ef302f7d9c1a1b7d22c54 100644
--- a/webrtc/modules/audio_coding/main/acm2/codec_manager.cc
+++ b/webrtc/modules/audio_coding/main/acm2/codec_manager.cc
@@ -13,8 +13,7 @@
 #include "webrtc/base/checks.h"
 #include "webrtc/engine_configurations.h"
 #include "webrtc/modules/audio_coding/main/acm2/acm_codec_database.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"
 #include "webrtc/system_wrappers/interface/trace.h"
 
 namespace webrtc {
@@ -155,7 +154,7 @@ bool CodecSupported(const CodecInst& codec) {
 const CodecInst kEmptyCodecInst = {-1, "noCodecRegistered", 0, 0, 0, 0};
 }  // namespace
 
-CodecManager::CodecManager()
+CodecManager::CodecManager(DelayedLogger* bitrate_logger)
     : cng_nb_pltype_(255),
       cng_wb_pltype_(255),
       cng_swb_pltype_(255),
@@ -166,7 +165,9 @@ CodecManager::CodecManager()
       vad_mode_(VADNormal),
       send_codec_inst_(kEmptyCodecInst),
       red_enabled_(false),
-      codec_fec_enabled_(false) {
+      codec_fec_enabled_(false),
+      codec_owner_(bitrate_logger),
+      bitrate_logger_(bitrate_logger) {
   // Register the default payload type for RED and for CNG at sampling rates of
   // 8, 16, 32 and 48 kHz.
   for (int i = (ACMCodecDB::kNumCodecs - 1); i >= 0; i--) {
@@ -314,9 +315,10 @@ int CodecManager::RegisterEncoder(const CodecInst& send_codec) {
   // Check if a change in Rate is required.
   if (send_codec.rate != send_codec_inst_.rate) {
     codec_owner_.SpeechEncoder()->SetTargetBitrate(send_codec.rate);
-    RTC_HISTOGRAM_COUNTS_100(
-        HISTOGRAM_NAME_AUDIO_TARGET_BITRATE_IN_KBPS,
-        codec_owner_.SpeechEncoder()->GetTargetBitrate() / 1000);
+    if (bitrate_logger_) {
+      bitrate_logger_->SetValue(
+          codec_owner_.SpeechEncoder()->GetTargetBitrate() / 1000);
+    }
     send_codec_inst_.rate = send_codec.rate;
   }