A simple copy of the old mixer to a new directory. I also plan to run 'git cl format'. In another C…

webrtc/modules/audio_mixer/include/audio_conference_mixer.h

+/*
+ *  Copyright (c) 2011 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.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_CONFERENCE_MIXER_INCLUDE_AUDIO_CONFERENCE_MIXER_H_
+#define WEBRTC_MODULES_AUDIO_CONFERENCE_MIXER_INCLUDE_AUDIO_CONFERENCE_MIXER_H_
+
+#include "webrtc/modules/audio_conference_mixer/include/audio_conference_mixer_defines.h"
+#include "webrtc/modules/include/module.h"
+#include "webrtc/modules/include/module_common_types.h"
+
+namespace webrtc {
+class AudioMixerOutputReceiver;
+class MixerParticipant;
+class Trace;
+
+class AudioConferenceMixer : public Module {
+ public:
+  enum { kMaximumAmountOfMixedParticipants = 3 };
+  enum Frequency {
+    kNbInHz = 8000,

[ossu, 2016/06/30 15:44:03]

I kinda like when things are aligned vertically; it makes it easier to read and
edit. Though it might be something to consider once you _actually_ start
rewriting these files.

+    kWbInHz = 16000,
+    kSwbInHz = 32000,
+    kFbInHz = 48000,
+    kLowestPossible = -1,
+    kDefaultFrequency = kWbInHz
+  };
+
+  // Factory method. Constructor disabled.
+  static AudioConferenceMixer* Create(int id);
+  virtual ~AudioConferenceMixer() {}
+
+  // Module functions
+  int64_t TimeUntilNextProcess() override = 0;
+  void Process() override = 0;
+
+  // Register/unregister a callback class for receiving the mixed audio.
+  virtual int32_t RegisterMixedStreamCallback(
+      AudioMixerOutputReceiver* receiver) = 0;
+  virtual int32_t UnRegisterMixedStreamCallback() = 0;
+
+  // Add/remove participants as candidates for mixing.
+  virtual int32_t SetMixabilityStatus(MixerParticipant* participant,
+                                      bool mixable) = 0;
+  // Returns true if a participant is a candidate for mixing.
+  virtual bool MixabilityStatus(const MixerParticipant& participant) const = 0;
+
+  // Inform the mixer that the participant should always be mixed and not
+  // count toward the number of mixed participants. Note that a participant
+  // must have been added to the mixer (by calling SetMixabilityStatus())
+  // before this function can be successfully called.
+  virtual int32_t SetAnonymousMixabilityStatus(MixerParticipant* participant,
+                                               bool mixable) = 0;
+  // Returns true if the participant is mixed anonymously.
+  virtual bool AnonymousMixabilityStatus(
+      const MixerParticipant& participant) const = 0;
+
+  // Set the minimum sampling frequency at which to mix. The mixing algorithm
+  // may still choose to mix at a higher samling frequency to avoid
+  // downsampling of audio contributing to the mixed audio.
+  virtual int32_t SetMinimumMixingFrequency(Frequency freq) = 0;
+
+ protected:
+  AudioConferenceMixer() {}
+};
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_CONFERENCE_MIXER_INCLUDE_AUDIO_CONFERENCE_MIXER_H_