Add sender controlled playout delay limits

webrtc/audio/audio_send_stream.cc

Index: webrtc/audio/audio_send_stream.cc
diff --git a/webrtc/audio/audio_send_stream.cc b/webrtc/audio/audio_send_stream.cc
index e9659c67e8c48ecd3bf09369d27562322b1e5be3..92be961a0ae2e2070e34c5ca480daa249a57fc08 100644
--- a/webrtc/audio/audio_send_stream.cc
+++ b/webrtc/audio/audio_send_stream.cc
@@ -85,6 +85,8 @@ AudioSendStream::AudioSendStream(
       channel_proxy_->SetSendAudioLevelIndicationStatus(true, extension.id);
     } else if (extension.uri == RtpExtension::kTransportSequenceNumberUri) {
       channel_proxy_->EnableSendTransportSequenceNumber(extension.id);
+    } else if (extension.uri == RtpExtension::kPlayoutDelayUri) {
+      channel_proxy_->EnableSendPlayoutDelayLimit(extension.id);
     } else {
       RTC_NOTREACHED() << "Registering unsupported RTP extension.";
     }