Optionally disable APM limiter in AudioMixer.

webrtc/modules/audio_mixer/BUILD.gn

Index: webrtc/modules/audio_mixer/BUILD.gn
diff --git a/webrtc/modules/audio_mixer/BUILD.gn b/webrtc/modules/audio_mixer/BUILD.gn
index 083e02b9ca6b8c4fd5b5494a08a067044a48dc65..507553355fca8938be50a07f6e0ce53d497fda40 100644
--- a/webrtc/modules/audio_mixer/BUILD.gn
+++ b/webrtc/modules/audio_mixer/BUILD.gn
@@ -21,11 +21,15 @@ rtc_static_library("audio_mixer_impl") {
     "audio_mixer_impl.h",
     "default_output_rate_calculator.cc",
     "default_output_rate_calculator.h",
+    "frame_combiner.cc",
+    "frame_combiner.h",
     "output_rate_calculator.h",
   ]
 
   public = [
     "audio_mixer_impl.h",
+    "default_output_rate_calculator.h",  # For creating a mixer with limiter disabled.
+    "frame_combiner.h",
   ]
 
   public_deps = [
@@ -61,14 +65,11 @@ rtc_static_library("audio_frame_manipulator") {
 
 if (rtc_include_tests) {
   rtc_source_set("audio_mixer_unittests") {
-    # When enabled, fails with error audio_mixer_impl_unittest.cc includes a
-    # private header. Fie default_output_rate_calculator.h is private to the
-    # target :audio_mixer_impl
-    check_includes = false
     testonly = true
     sources = [
       "audio_frame_manipulator_unittest.cc",
       "audio_mixer_impl_unittest.cc",
+      "frame_combiner_unittest.cc",
     ]
     deps = [
       ":audio_frame_manipulator",
@@ -79,12 +80,5 @@ if (rtc_include_tests) {
       "../../test:test_support",
       "//testing/gmock",
     ]
-
-    # TODO(jschuh): bugs.webrtc.org/1348: fix this warning.
-    configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
-    if (!build_with_chromium && is_clang) {
-      # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
-      suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
-    }
   }
 }