AGC: Route clipping parameter from webrtc::Config to AGC

This change enables experimentation with the clipping minimum level
parameter in the gain control.

BUG=webrtc:6622
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_rel_ng

Review-Url: https://codereview.webrtc.org/2543753006
Cr-Commit-Position: refs/heads/master@{#15426}
diff --git a/webrtc/modules/audio_processing/audio_processing_impl.h b/webrtc/modules/audio_processing/audio_processing_impl.h
index 4db2272..0375a25 100644
--- a/webrtc/modules/audio_processing/audio_processing_impl.h
+++ b/webrtc/modules/audio_processing/audio_processing_impl.h
@@ -329,11 +329,15 @@
 
   // APM constants.
   const struct ApmConstants {
-    ApmConstants(int agc_startup_min_volume, bool use_experimental_agc)
+    ApmConstants(int agc_startup_min_volume,
+                 int agc_clipped_level_min,
+                 bool use_experimental_agc)
         :  // Format of processing streams at input/output call sites.
           agc_startup_min_volume(agc_startup_min_volume),
+          agc_clipped_level_min(agc_clipped_level_min),
           use_experimental_agc(use_experimental_agc) {}
     int agc_startup_min_volume;
+    int agc_clipped_level_min;
     bool use_experimental_agc;
   } constants_;