Added empty directory with myself as owner for new mixer.

webrtc/modules/audio_mixer/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 config("audio_conference_mixer_config") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
   include_dirs = [
     "include",
-    "../include",
+    "../../modules/include",
   ]
 }
 
+source_set("audio_mixer") {
+  sources = [
+    "audio_mixer.cc",
+    "audio_mixer.h",
+  ]
+  deps = [
+    ":audio_conference_mixer",
+  ]
+
+  if (is_win) {
+    defines = [ "WEBRTC_DRIFT_COMPENSATION_SUPPORTED" ]
+
+    cflags = [
+      # TODO(kjellander): Bug 261: fix this warning.
+      "/wd4373",  # virtual function override.
+    ]
+  }
+
+  configs += [ "../..:common_config" ]
+  public_configs = [ "../..:common_inherited_config" ]
+
+  if (is_clang) {
+    # Suppress warnings from Chrome's Clang plugins.
+    # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
+    configs -= [ "//build/config/clang:find_bad_constructs" ]
+  }
+}
+
 source_set("audio_conference_mixer") {
   sources = [
     "include/audio_conference_mixer.h",
     "include/audio_conference_mixer_defines.h",
     "source/audio_conference_mixer_impl.cc",
     "source/audio_conference_mixer_impl.h",
-    "source/audio_frame_manipulator.cc",
-    "source/audio_frame_manipulator.h",
-    "source/memory_pool.h",
-    "source/memory_pool_posix.h",
-    "source/memory_pool_win.h",
-    "source/time_scheduler.cc",
-    "source/time_scheduler.h",
   ]
 
   configs += [ "../..:common_config" ]
 
   public_configs = [
     "../..:common_inherited_config",
     ":audio_conference_mixer_config",
   ]
 
   if (is_clang) {
     # Suppress warnings from Chrome's Clang plugins.
     # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
     configs -= [ "//build/config/clang:find_bad_constructs" ]
   }
 
   deps = [
+    "../../modules/audio_processing",
+    "../../modules/utility",
     "../../system_wrappers",
-    "../audio_processing",
-    "../utility",
   ]
 }