Implement ANA statistics.

webrtc/modules/audio_coding/audio_network_adaptor/audio_network_adaptor_impl.h

 /*
  *  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.
  */
 
@@ skipping 57 matching lines @@
   const Config config_;
 
   std::unique_ptr<ControllerManager> controller_manager_;
 
   std::unique_ptr<DebugDumpWriter> debug_dump_writer_;
 
   const std::unique_ptr<EventLogWriter> event_log_writer_;
 
   Controller::NetworkMetrics last_metrics_;
 
+  rtc::Optional<AudioEncoderRuntimeConfig> prev_config_;
+
+  ANAStats stats_;
+
+  const bool enable_bitrate_adaptation_;
+  const bool enable_dtx_adaptation_;
+  const bool enable_fec_adaptation_;
+  const bool enable_channel_adaptation_;
+  const bool enable_frame_length_adaptation_;
+
   RTC_DISALLOW_COPY_AND_ASSIGN(AudioNetworkAdaptorImpl);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_CODING_AUDIO_NETWORK_ADAPTOR_AUDIO_NETWORK_ADAPTOR_IMPL_H_