Make the audio channel communicate network state changes to the call.

webrtc/modules/pacing/paced_sender.cc

Index: webrtc/modules/pacing/paced_sender.cc
diff --git a/webrtc/modules/pacing/paced_sender.cc b/webrtc/modules/pacing/paced_sender.cc
index 699865097985dbe896ab77739fc9a1ded12a565a..b6357f0158e076e45a509a9add7d9326d3a11ca8 100644
--- a/webrtc/modules/pacing/paced_sender.cc
+++ b/webrtc/modules/pacing/paced_sender.cc
@@ -379,7 +379,8 @@ void PacedSender::Process() {
   int64_t elapsed_time_ms = (now_us - time_last_update_us_ + 500) / 1000;
   time_last_update_us_ = now_us;
   int target_bitrate_kbps = max_bitrate_kbps_;
-  // TODO(holmer): Remove the !paused_ check when issue 5307 has been fixed.
+  // TODO(skvlad): Remove the !paused_ check when media channel state tracking
+  // is correctly implemented in call.cc
   if (!paused_ && elapsed_time_ms > 0) {
     size_t queue_size_bytes = packets_->SizeInBytes();
     if (queue_size_bytes > 0) {
@@ -421,7 +422,8 @@ void PacedSender::Process() {
     }
   }
 
-  // TODO(holmer): Remove the paused_ check when issue 5307 has been fixed.
+  // TODO(skvlad): Remove the paused_ check when media channel state tracking
+  // is correctly implemented in call.cc
   if (paused_ || !packets_->Empty())
     return;
 
@@ -437,9 +439,12 @@ void PacedSender::Process() {
 }
 
 bool PacedSender::SendPacket(const paced_sender::Packet& packet) {
-  // TODO(holmer): Because of this bug issue 5307 we have to send audio
-  // packets even when the pacer is paused. Here we assume audio packets are
-  // always high priority and that they are the only high priority packets.
+  // TODO(skvlad): Even though issue 5307 is fixed, we're keeping the
+  // workaround to send audio packets when the pacer is paused until accurate
+  // tracking of the state of audio and video MediaChannels is implemented in
+  // call.cc.
+  // Here we assume audio packets are always high priority and that they are
+  // the only high priority packets.
   if (paused_ && packet.priority != kHighPriority)
     return false;
   critsect_->Leave();