AGC2 dummy module: fixed gain param, APM integration, audioproc_f adaptation

webrtc/modules/audio_processing/agc2/digital_gain_applier.h

-/*
- *  Copyright (c) 2017 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_PROCESSING_AGC2_DIGITAL_GAIN_APPLIER_H_
-#define WEBRTC_MODULES_AUDIO_PROCESSING_AGC2_DIGITAL_GAIN_APPLIER_H_
-
-#include "webrtc/api/array_view.h"
-#include "webrtc/modules/audio_processing/audio_buffer.h"
-
-namespace webrtc {
-
-class DigitalGainApplier {
- public:
-  DigitalGainApplier();
-
-  // Applies the specified gain to an array of samples.
-  void Process(float gain, rtc::ArrayView<float> samples);
-
- private:
-  void LimitToAllowedRange(rtc::ArrayView<float> x);
-};
-
-}  // namespace webrtc
-
-#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AGC2_DIGITAL_GAIN_APPLIER_H_