Add time line for acked bitrate.

webrtc/voice_engine/channel.cc

Index: webrtc/voice_engine/channel.cc
diff --git a/webrtc/voice_engine/channel.cc b/webrtc/voice_engine/channel.cc
index d6daffddf83ee0f751d59665e85b15d89ff2622b..61e1336468006cc65bd2d133fc899da58549f1c5 100644
--- a/webrtc/voice_engine/channel.cc
+++ b/webrtc/voice_engine/channel.cc
@@ -166,11 +166,14 @@ class TransportFeedbackProxy : public TransportFeedbackObserver {
     if (feedback_observer_)
       feedback_observer_->AddPacket(sequence_number, length, probe_cluster_id);
   }
-  void OnTransportFeedback(const rtcp::TransportFeedback& feedback) override {
+  std::vector<PacketInfo> OnTransportFeedback(
+      const rtcp::TransportFeedback& feedback) override {
     RTC_DCHECK(network_thread_.CalledOnValidThread());
     rtc::CritScope lock(&crit_);
+    std::vector<PacketInfo> feedback_vector;
     if (feedback_observer_)
-      feedback_observer_->OnTransportFeedback(feedback);
+      feedback_vector = feedback_observer_->OnTransportFeedback(feedback);
+    return feedback_vector;
   }
 
  private: