Add Audio support in Chromoting host when using WebRTC.

remoting/host/chromoting_host.cc

Index: remoting/host/chromoting_host.cc
diff --git a/remoting/host/chromoting_host.cc b/remoting/host/chromoting_host.cc
index 0dd25a957dff15bc79fadf0836494b88eae9a6b1..d2c0232e7144616804cedf2bbbf000774462787d 100644
--- a/remoting/host/chromoting_host.cc
+++ b/remoting/host/chromoting_host.cc
@@ -268,7 +268,7 @@ void ChromotingHost::OnIncomingSession(
       protocol::SessionConfig::Protocol::WEBRTC) {
     connection.reset(new protocol::WebrtcConnectionToClient(
         base::WrapUnique(session), transport_context_,
-        video_encode_task_runner_));
+        video_encode_task_runner_, audio_task_runner_));
   } else {
     connection.reset(new protocol::IceConnectionToClient(
         base::WrapUnique(session), transport_context_,