Reland of added functionality for specifying the initial signal level to use for the gain estimation

webrtc/modules/audio_processing/level_controller/peak_level_estimator.h

Index: webrtc/modules/audio_processing/level_controller/peak_level_estimator.h
diff --git a/webrtc/modules/audio_processing/level_controller/peak_level_estimator.h b/webrtc/modules/audio_processing/level_controller/peak_level_estimator.h
index 270bbc3ad0a1e9e7960a36892033b2ea5947d778..d8264d7302dca8479ed342741563f7e57a1a46e5 100644
--- a/webrtc/modules/audio_processing/level_controller/peak_level_estimator.h
+++ b/webrtc/modules/audio_processing/level_controller/peak_level_estimator.h
@@ -12,6 +12,7 @@
 #define WEBRTC_MODULES_AUDIO_PROCESSING_LEVEL_CONTROLLER_PEAK_LEVEL_ESTIMATOR_H_
 
 #include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/audio_processing/level_controller/lc_constants.h"
 #include "webrtc/modules/audio_processing/level_controller/signal_classifier.h"
 
 namespace webrtc {
@@ -23,9 +24,14 @@ class PeakLevelEstimator {
   void Initialize();
   float Analyze(SignalClassifier::SignalType signal_type,
                 float frame_peak_level);
+  // Sets the initial peak level to use inside the level controller in order
+  // to compute the signal gain. The unit for the peak level is dBFS and
+  // the allowed range is [-100, 0].
+  void SetInitialPeakLevel(float level);
 
  private:
   float peak_level_;
+  float initial_peak_level_ = kTargetLcPeakLevel;
   int hold_counter_;
   bool initialization_phase_;