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 b4d875934b0fc22265f651dc76275cfe7c4d5522..25c47ec9641c8e957e148d8c341184b0d892852a 100644
--- a/webrtc/modules/audio_processing/BUILD.gn
+++ b/webrtc/modules/audio_processing/BUILD.gn
@@ -46,7 +46,6 @@ rtc_static_library("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",
@@ -68,6 +67,7 @@ rtc_static_library("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",
@@ -79,9 +79,9 @@ rtc_static_library("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",