Log audio network adapter decisions in event log.

webrtc/logging/rtc_event_log/rtc_event_log.cc

Index: webrtc/logging/rtc_event_log/rtc_event_log.cc
diff --git a/webrtc/logging/rtc_event_log/rtc_event_log.cc b/webrtc/logging/rtc_event_log/rtc_event_log.cc
index 976ff2321c08106dcea319a19c63f50619ebb0af..96d6e56d653fcd6633f5c10ff9d7391d291cc336 100644
--- a/webrtc/logging/rtc_event_log/rtc_event_log.cc
+++ b/webrtc/logging/rtc_event_log/rtc_event_log.cc
@@ -77,6 +77,8 @@ class RtcEventLogImpl final : public RtcEventLog {
   void LogBwePacketLossEvent(int32_t bitrate,
                              uint8_t fraction_loss,
                              int32_t total_packets) override;
+  void LogEncoderRuntimeConfig(
+      const AudioNetworkAdaptor::EncoderRuntimeConfig& config) override;
 
  private:
   void StoreEvent(std::unique_ptr<rtclog::Event>* event);
@@ -437,6 +439,28 @@ void RtcEventLogImpl::LogBwePacketLossEvent(int32_t bitrate,
   StoreEvent(&event);
 }
 
+void RtcEventLogImpl::LogEncoderRuntimeConfig(
+    const AudioNetworkAdaptor::EncoderRuntimeConfig& config) {
+  std::unique_ptr<rtclog::Event> event(new rtclog::Event());
+  event->set_timestamp_us(clock_->TimeInMicroseconds());
+  event->set_type(rtclog::Event::AUDIO_NETWORK_ADAPTOR_EVENT);

[minyue-webrtc, 2016/12/20 10:39:29]

Slightly confusing is that the function is LogEncoderRuntimeConfig and the event
type is AUDIO_NETWORK_ADAPTOR_EVENT;

Can we change the event type and the function name to

LogAudioEncoderConfig and AUDIO_ENCODER_CONFIG_EVENT, For brevity, I throw
"runtime" away. Since the log is a time series, "runtime" is implicit.

[michaelt, 2016/12/20 13:41:41]

Done.

[minyue-webrtc, 2016/12/20 14:11:05]

Almost, but we cannot drop "Audio" in the function name.

[michaelt, 2016/12/20 14:34:03]

Right :)
Done

+  auto ana_event = event->mutable_encoder_runtime_config();
+  if (config.bitrate_bps)

[minyue-webrtc, 2016/12/20 10:39:29]

how about making 448 ~ 460 a utility function, which can be also used in
debug_dump_writer.cc? Then event log here does not need to care the content. 

where to put it? hmm, for simplicity, I don't mind first making it a static
method in debug_dump_writer. The method can be called 

[michaelt, 2016/12/20 13:41:40]

Done.

+    ana_event->set_bitrate_bps(*config.bitrate_bps);
+  if (config.frame_length_ms)
+    ana_event->set_frame_length_ms(*config.frame_length_ms);
+  if (config.uplink_packet_loss_fraction)
+    ana_event->set_uplink_packet_loss_fraction(
+        *config.uplink_packet_loss_fraction);
+  if (config.enable_fec)
+    ana_event->set_enable_fec(*config.enable_fec);
+  if (config.enable_dtx)
+    ana_event->set_enable_dtx(*config.enable_dtx);
+  if (config.num_channels)
+    ana_event->set_num_channels(*config.num_channels);
+  StoreEvent(&event);
+}
+
 void RtcEventLogImpl::StoreEvent(std::unique_ptr<rtclog::Event>* event) {
   if (!event_queue_.Insert(event)) {
     LOG(LS_ERROR) << "WebRTC event log queue full. Dropping event.";