Refactor webrtc/modules/audio_conference_mixer for GN check

webrtc/modules/audio_conference_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.
 
 import("../../build/webrtc.gni")
 
@@ skipping 21 matching lines @@
   ]
 
   public_configs = [ ":audio_conference_mixer_config" ]
 
   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" ]
   }
 
   deps = [
+    "../..:webrtc_common",
     "../../audio/utility:audio_frame_operations",
+    "../../base:rtc_base_approved",
     "../../system_wrappers",
     "../audio_processing",
   ]
 }