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

webrtc/modules/audio_processing/BUILD.gn

Index: webrtc/modules/audio_processing/BUILD.gn
diff --git a/webrtc/modules/audio_processing/BUILD.gn b/webrtc/modules/audio_processing/BUILD.gn
index 2387c2e85b375f819b50960969716978c14a1240..cec373be1f7f8f8322b7e23b141308254c20d326 100644
--- a/webrtc/modules/audio_processing/BUILD.gn
+++ b/webrtc/modules/audio_processing/BUILD.gn
@@ -48,7 +48,6 @@ rtc_source_set("audio_processing") {
     "agc/utility.h",
     "audio_buffer.cc",
     "audio_buffer.h",
-    "audio_processing.cc",
     "audio_processing_impl.cc",
     "audio_processing_impl.h",
     "beamformer/array_util.cc",
@@ -70,6 +69,7 @@ rtc_source_set("audio_processing") {
     "gain_control_impl.h",
     "high_pass_filter_impl.cc",
     "high_pass_filter_impl.h",
+    "include/audio_processing.cc",
     "include/audio_processing.h",
     "include/config.cc",
     "include/config.h",
@@ -81,9 +81,9 @@ rtc_source_set("audio_processing") {
     "level_controller/gain_applier.h",
     "level_controller/gain_selector.cc",
     "level_controller/gain_selector.h",
-    "level_controller/lc_constants.h",
     "level_controller/level_controller.cc",
     "level_controller/level_controller.h",
+    "level_controller/level_controller_constants.h",
     "level_controller/noise_level_estimator.cc",
     "level_controller/noise_level_estimator.h",
     "level_controller/noise_spectrum_estimator.cc",