Implemented the GetSources() in native code.

webrtc/voice_engine/channel_proxy.h

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 11 matching lines @@
 #include <string>
 #include <vector>
 
 namespace webrtc {
 
 class AudioSinkInterface;
 class PacketRouter;
 class RtcEventLog;
 class RtcpBandwidthObserver;
 class RtcpRttStats;
+class RtpContributingSource;
 class RtpPacketSender;
 class RtpPacketReceived;
 class RtpReceiver;
 class RtpRtcp;
 class RtpTransportControllerSendInterface;
 class Transport;
 class TransportFeedbackObserver;
 
 namespace voe {
 
@@ skipping 71 matching lines @@
   virtual bool SetVADStatus(bool enable);
   virtual bool SetCodecFECStatus(bool enable);
   virtual bool SetOpusDtx(bool enable);
   virtual bool SetOpusMaxPlaybackRate(int frequency_hz);
   virtual bool SetSendCodec(const CodecInst& codec_inst);
   virtual bool SetSendCNPayloadType(int type, PayloadFrequencies frequency);
   virtual void OnTwccBasedUplinkPacketLossRate(float packet_loss_rate);
   virtual void OnRecoverableUplinkPacketLossRate(
       float recoverable_packet_loss_rate);
   virtual void RegisterLegacyReceiveCodecs();
+  virtual const std::vector<RtpContributingSource*>& GetContributingSources();
 
  private:
   Channel* channel() const;
 
   // Thread checkers document and lock usage of some methods on voe::Channel to
   // specific threads we know about. The goal is to eventually split up
   // voe::Channel into parts with single-threaded semantics, and thereby reduce
   // the need for locks.
   rtc::ThreadChecker worker_thread_checker_;
   rtc::ThreadChecker module_process_thread_checker_;
   // Methods accessed from audio and video threads are checked for sequential-
   // only access. We don't necessarily own and control these threads, so thread
   // checkers cannot be used. E.g. Chromium may transfer "ownership" from one
   // audio thread to another, but access is still sequential.
   rtc::RaceChecker audio_thread_race_checker_;
   rtc::RaceChecker video_capture_thread_race_checker_;
   ChannelOwner channel_owner_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(ChannelProxy);
 };
 }  // namespace voe
 }  // namespace webrtc
 
 #endif  // WEBRTC_VOICE_ENGINE_CHANNEL_PROXY_H_