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 54 matching lines @@
         [](float a, float b) { return std::abs(a) < std::abs(b); });
     peak_level = std::max(*channel_peak_level, peak_level);
   }
   return peak_level;
 }
 
 const int kMetricsFrameInterval = 1000;
 
 }  // namespace
 
+bool AudioProcessing::Config::LevelController::Validate() const {

[the sun, 2016/08/30 18:05:35]

How about a static function in LevelController instead:

bool LevelController::Validate(const
AudioProcessing::Config::LevelControllerConfig& config) {
?

That will be easy to change into
bool LevelController::Validate(const LevelController::Config& config) {
once we get there.

Adding the function definition here, of something declared in AudioProcessing,
is confusing, and likely validates the style guide (or it should).

[peah-webrtc, 2016/08/31 08:08:32]

That sounds good!
Done.

+  return true;
+}
+
 int LevelController::instance_count_ = 0;
 
 void LevelController::Metrics::Initialize(int sample_rate_hz) {
   RTC_DCHECK(sample_rate_hz == AudioProcessing::kSampleRate8kHz ||
              sample_rate_hz == AudioProcessing::kSampleRate16kHz ||
              sample_rate_hz == AudioProcessing::kSampleRate32kHz ||
              sample_rate_hz == AudioProcessing::kSampleRate48kHz);
 
   Reset();
   frame_length_ = rtc::CheckedDivExact(sample_rate_hz, 100);
@@ skipping 171 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);
 }
 
 }  // namespace webrtc