Introduced new scheme for controlling the functionality inside the audio processing module

webrtc/modules/audio_processing/level_controller/level_controller.cc

 /*
  *  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 244 matching lines @@
 
   data_dumper_->DumpRaw("lc_selected_gain", 1, &last_gain_);
   data_dumper_->DumpRaw("lc_noise_energy", 1, &noise_energy);
   data_dumper_->DumpRaw("lc_peak_level", 1, &long_term_peak_level);
   data_dumper_->DumpRaw("lc_saturating_gain", 1, &saturating_gain);
 
   data_dumper_->DumpWav("lc_output", audio->num_frames(),
                         audio->channels_f()[0], *sample_rate_hz_, 1);
 }
 
+std::string LevelController::ToString(
+    const AudioProcessing::Config::LevelController& config) {
+  std::stringstream ss;
+  ss << "{ LevelController config: "

[the sun, 2016/09/08 09:45:55]

Sorry, I should've noticed: only name the individual fields and output their
respective values (see audio_receive_stream.cc). The method calling this
function should do e.g.:
ss << "level_controller: " << level_controller.ToString();
So, no "LevelController config:" in this function.

By following this approach, our log statements are more easily machine
parseable.

[peah-webrtc, 2016/09/08 19:34:25]

Done.

+     << "{"
+     << "enabled=" << (config.enabled ? "true" : "false") << "}";

[the sun, 2016/09/08 09:45:55]

"enabled: "

[peah-webrtc, 2016/09/08 19:34:25]

Done.

+  return ss.str();
+}
+
+AudioProcessing::Config::LevelController LevelController::DefaultConfig() {
+  AudioProcessing::Config::LevelController config;
+  config.enabled = false;
+  return config;
+}
+
+bool LevelController::Validate(
+    const AudioProcessing::Config::LevelController& config) {
+  return true;
+}
+
 }  // namespace webrtc