Add Audio support in Chromoting host when using WebRTC.

remoting/protocol/fake_audio_source.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "remoting/protocol/ice_config.h"
+#include "remoting/protocol/fake_audio_source.h"
 
 namespace remoting {
 namespace protocol {
 
-IceConfig::IceConfig() {}
-IceConfig::IceConfig(const IceConfig& other) = default;
-IceConfig::~IceConfig() {}
+FakeAudioSource::FakeAudioSource() {}
+FakeAudioSource::~FakeAudioSource() {}
+
+bool FakeAudioSource::Start(const PacketCapturedCallback& callback) {
+  callback_ = callback;
+  return true;
+}
 
 }  // namespace protocol
 }  // namespace remoting