Delete unused class AudioSourceWithMixStatus.

BUG=webrtc:6346

Review-Url: https://codereview.webrtc.org/2437863003
Cr-Commit-Position: refs/heads/master@{#14728}
diff --git a/webrtc/modules/audio_mixer/BUILD.gn b/webrtc/modules/audio_mixer/BUILD.gn
index 26adcf8..41aaab0 100644
--- a/webrtc/modules/audio_mixer/BUILD.gn
+++ b/webrtc/modules/audio_mixer/BUILD.gn
@@ -16,8 +16,6 @@
   sources = [
     "audio_mixer_impl.cc",
     "audio_mixer_impl.h",
-    "audio_source_with_mix_status.cc",
-    "audio_source_with_mix_status.h",
   ]
 
   public = [
diff --git a/webrtc/modules/audio_mixer/audio_mixer.gypi b/webrtc/modules/audio_mixer/audio_mixer.gypi
index ee40a9c..23821cb 100644
--- a/webrtc/modules/audio_mixer/audio_mixer.gypi
+++ b/webrtc/modules/audio_mixer/audio_mixer.gypi
@@ -22,8 +22,6 @@
       'sources': [
         'audio_mixer_impl.cc',
         'audio_mixer_impl.h',
-        'audio_source_with_mix_status.cc',
-        'audio_source_with_mix_status.h',
       ],
     },
     {
diff --git a/webrtc/modules/audio_mixer/audio_source_with_mix_status.cc b/webrtc/modules/audio_mixer/audio_source_with_mix_status.cc
deleted file mode 100644
index db94887..0000000
--- a/webrtc/modules/audio_mixer/audio_source_with_mix_status.cc
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- *  Copyright (c) 2016 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.
- */
-
-#include "webrtc/modules/audio_mixer/audio_source_with_mix_status.h"
-
-namespace webrtc {
-
-AudioSourceWithMixStatus::AudioSourceWithMixStatus(
-    AudioMixer::Source* audio_source)
-    : audio_source_(audio_source) {}
-
-AudioSourceWithMixStatus::~AudioSourceWithMixStatus() {}
-
-bool AudioSourceWithMixStatus::IsMixed() const {
-  return is_mixed_;
-}
-
-bool AudioSourceWithMixStatus::WasMixed() const {
-  // Was mixed is the same as is mixed depending on perspective. This function
-  // is for the perspective of AudioMixerImpl.
-  return IsMixed();
-}
-
-void AudioSourceWithMixStatus::SetIsMixed(const bool mixed) {
-  is_mixed_ = mixed;
-}
-
-void AudioSourceWithMixStatus::ResetMixedStatus() {
-  is_mixed_ = false;
-}
-
-AudioMixer::Source* AudioSourceWithMixStatus::audio_source() const {
-  return audio_source_;
-}
-
-}  // namespace webrtc
diff --git a/webrtc/modules/audio_mixer/audio_source_with_mix_status.h b/webrtc/modules/audio_mixer/audio_source_with_mix_status.h
deleted file mode 100644
index 4849d61..0000000
--- a/webrtc/modules/audio_mixer/audio_source_with_mix_status.h
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- *  Copyright (c) 2016 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_MIXER_AUDIO_SOURCE_WITH_MIX_STATUS_H_
-#define WEBRTC_MODULES_AUDIO_MIXER_AUDIO_SOURCE_WITH_MIX_STATUS_H_
-
-#include "webrtc/api/audio/audio_mixer.h"
-
-namespace webrtc {
-
-// A class that holds a mixer participant and its mixing status.
-class AudioSourceWithMixStatus {
- public:
-  explicit AudioSourceWithMixStatus(AudioMixer::Source* audio_source);
-  ~AudioSourceWithMixStatus();
-
-  AudioSourceWithMixStatus(const AudioSourceWithMixStatus&) = default;
-
-  // Returns true if the audio source was mixed this mix iteration.
-  bool IsMixed() const;
-
-  // Returns true if the audio source was mixed previous mix
-  // iteration.
-  bool WasMixed() const;
-
-  // Updates the mixed status.
-  void SetIsMixed(const bool mixed);
-  void ResetMixedStatus();
-  AudioMixer::Source* audio_source() const;
-
- private:
-  AudioMixer::Source* audio_source_ = nullptr;
-  bool is_mixed_ = false;
-};
-
-}  // namespace webrtc
-
-#endif  // WEBRTC_MODULES_AUDIO_MIXER_AUDIO_SOURCE_WITH_MIX_STATUS_H_