Fix style guide issues in audio 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.
 
 import("../../build/webrtc.gni")
 
@@ skipping 11 matching lines @@
     "audio_mixer_impl.h",
   ]
 
   public = [
     "audio_mixer_defines.h",
     "audio_mixer.h",
   ]
 
   public_configs = [ ":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.
-    suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
-  }
-
   deps = [
     "../..:webrtc_common",
     "../../base:rtc_base_approved",
     "../../modules/audio_processing",
     "../../modules/utility",
     "../../system_wrappers",
     "../../voice_engine:level_indicator",
   ]
 }