Remove interface directories kept to avoid breaking downstream.

webrtc/modules/audio_conference_mixer/interface/audio_conference_mixer_defines.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_DEFINES_H_
-#define WEBRTC_MODULES_AUDIO_CONFERENCE_MIXER_INCLUDE_AUDIO_CONFERENCE_MIXER_DEFINES_H_
-
-#pragma message("WARNING: audio_conference_mixer/interface is DEPRECATED; use include")
-
-#include "webrtc/modules/include/module_common_types.h"
-#include "webrtc/typedefs.h"
-
-namespace webrtc {
-class MixHistory;
-
-// A callback class that all mixer participants must inherit from/implement.
-class MixerParticipant
-{
-public:
-    // The implementation of this function should update audioFrame with new
-    // audio every time it's called.
-    //
-    // If it returns -1, the frame will not be added to the mix.
-    virtual int32_t GetAudioFrame(int32_t id,
-                                  AudioFrame* audioFrame) = 0;
-
-    // Returns true if the participant was mixed this mix iteration.
-    bool IsMixed() const;
-
-    // This function specifies the sampling frequency needed for the AudioFrame
-    // for future GetAudioFrame(..) calls.
-    virtual int32_t NeededFrequency(int32_t id) const = 0;
-
-    MixHistory* _mixHistory;
-protected:
-    MixerParticipant();
-    virtual ~MixerParticipant();
-};
-
-class AudioMixerOutputReceiver
-{
-public:
-    // This callback function provides the mixed audio for this mix iteration.
-    // Note that uniqueAudioFrames is an array of AudioFrame pointers with the
-    // size according to the size parameter.
-    virtual void NewMixedAudio(const int32_t id,
-                               const AudioFrame& generalAudioFrame,
-                               const AudioFrame** uniqueAudioFrames,
-                               const uint32_t size) = 0;
-protected:
-    AudioMixerOutputReceiver() {}
-    virtual ~AudioMixerOutputReceiver() {}
-};
-}  // namespace webrtc
-
-#endif // WEBRTC_MODULES_AUDIO_CONFERENCE_MIXER_INCLUDE_AUDIO_CONFERENCE_MIXER_DEFINES_H_