Support external audio mixer in webrtc 2.

webrtc/media/base/fakemediaengine.h

 /*
  *  Copyright (c) 2004 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 735 matching lines @@
   // Flag used by optionsmessagehandler_unittest for checking whether any
   // relevant setting has been updated.
   // TODO(thaloun): Replace with explicit checks of before & after values.
   bool options_changed_;
   bool fail_create_channel_;
   RtpCapabilities capabilities_;
 };
 
 class FakeVoiceEngine : public FakeBaseEngine {
  public:
-  FakeVoiceEngine(
-      webrtc::AudioDeviceModule* adm,
-      const rtc::scoped_refptr<webrtc::AudioDecoderFactory>&
-          audio_decoder_factory) {
+  FakeVoiceEngine(webrtc::AudioDeviceModule* adm,
+                  const rtc::scoped_refptr<webrtc::AudioDecoderFactory>&
+                      audio_decoder_factory,
+                  rtc::scoped_refptr<webrtc::AudioMixer> audio_mixer) {
     // Add a fake audio codec. Note that the name must not be "" as there are
     // sanity checks against that.
     codecs_.push_back(AudioCodec(101, "fake_audio_codec", 0, 0, 1));
   }
   rtc::scoped_refptr<webrtc::AudioState> GetAudioState() const {
     return rtc::scoped_refptr<webrtc::AudioState>();
   }
 
   VoiceMediaChannel* CreateChannel(webrtc::Call* call,
                                    const MediaConfig& config,
@@ skipping 87 matching lines @@
   VideoOptions options_;
 
   friend class FakeMediaEngine;
 };
 
 class FakeMediaEngine :
     public CompositeMediaEngine<FakeVoiceEngine, FakeVideoEngine> {
  public:
   FakeMediaEngine()
       : CompositeMediaEngine<FakeVoiceEngine, FakeVideoEngine>(nullptr,
+                                                               nullptr,
                                                                nullptr) {}
   virtual ~FakeMediaEngine() {}
 
   void SetAudioCodecs(const std::vector<AudioCodec>& codecs) {
     voice_.SetCodecs(codecs);
   }
   void SetVideoCodecs(const std::vector<VideoCodec>& codecs) {
     video_.SetCodecs(codecs);
   }
 
@@ skipping 92 matching lines @@
 
  private:
   std::vector<FakeDataMediaChannel*> channels_;
   std::vector<DataCodec> data_codecs_;
   DataChannelType last_channel_type_;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_BASE_FAKEMEDIAENGINE_H_