Move RtcEventLog object from inside VoiceEngine to Call.

webrtc/audio/audio_receive_stream.cc

Index: webrtc/audio/audio_receive_stream.cc
diff --git a/webrtc/audio/audio_receive_stream.cc b/webrtc/audio/audio_receive_stream.cc
index 9c253894719278a48b354763b4aef0a3235d0817..c0a29b24b588f846ae3a608933ac59463b4b025a 100644
--- a/webrtc/audio/audio_receive_stream.cc
+++ b/webrtc/audio/audio_receive_stream.cc
@@ -82,7 +82,8 @@ namespace internal {
 AudioReceiveStream::AudioReceiveStream(
     CongestionController* congestion_controller,
     const webrtc::AudioReceiveStream::Config& config,
-    const rtc::scoped_refptr<webrtc::AudioState>& audio_state)
+    const rtc::scoped_refptr<webrtc::AudioState>& audio_state,
+    webrtc::RtcEventLog* event_log)
     : config_(config),
       audio_state_(audio_state),
       rtp_header_parser_(RtpHeaderParser::Create()) {
@@ -94,6 +95,7 @@ AudioReceiveStream::AudioReceiveStream(
 
   VoiceEngineImpl* voe_impl = static_cast<VoiceEngineImpl*>(voice_engine());
   channel_proxy_ = voe_impl->GetChannelProxy(config_.voe_channel_id);
+  channel_proxy_->SetRtcEventLog(event_log);

[tommi, 2016/04/04 14:26:47]

how is ownership and lifetime of |event_log| managed?

[ivoc, 2016/04/05 08:02:58]

|event_log| is a member of Call, which should outlive its AudioReceiveStreams
(although this relationship is not very explicit in the code). 
I think it's common for raw pointers of Call-members to be passed to the various
send/receive Streams, see the CongestionController* above for another example.

[tommi, 2016/04/07 13:21:53]

As a pattern, I think it's one to avoid if we can - even though we have examples
of it.
If you're sure that we're at least as safe here as we are with the pointer to
CongestionController (i.e. they have the same lifetime), then that's good enough
for now.

   channel_proxy_->SetLocalSSRC(config.rtp.local_ssrc);
   for (const auto& extension : config.rtp.extensions) {
     if (extension.name == RtpExtension::kAudioLevel) {
@@ -128,6 +130,7 @@ AudioReceiveStream::~AudioReceiveStream() {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   LOG(LS_INFO) << "~AudioReceiveStream: " << config_.ToString();
   channel_proxy_->ResetCongestionControlObjects();
+  channel_proxy_->SetRtcEventLog(nullptr);
   if (remote_bitrate_estimator_) {
     remote_bitrate_estimator_->RemoveStream(config_.rtp.remote_ssrc);
   }