Don't link with audio codecs that we don't use

webrtc/build/common.gypi

 # Copyright (c) 2012 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.
 
 # This file contains common settings for building WebRTC components.
 
@@ skipping 24 matching lines @@
       },
       'build_with_chromium%': '<(build_with_chromium)',
       'build_with_libjingle%': '<(build_with_libjingle)',
       'webrtc_root%': '<(webrtc_root)',
       'apk_tests_path%': '<(apk_tests_path)',
       'modules_java_gyp_path%': '<(modules_java_gyp_path)',
       'webrtc_vp8_dir%': '<(webrtc_root)/modules/video_coding/codecs/vp8',
       'webrtc_vp9_dir%': '<(webrtc_root)/modules/video_coding/codecs/vp9',
       'include_opus%': 1,
       'opus_dir%': '<(DEPTH)/third_party/opus',
+
+      # Enable to use the Mozilla internal settings.
+      'build_with_mozilla%': 0,
     },
     'build_with_chromium%': '<(build_with_chromium)',
     'build_with_libjingle%': '<(build_with_libjingle)',
+    'build_with_mozilla%': '<(build_with_mozilla)',
     'webrtc_root%': '<(webrtc_root)',
     'apk_tests_path%': '<(apk_tests_path)',
     'modules_java_gyp_path%': '<(modules_java_gyp_path)',
     'webrtc_vp8_dir%': '<(webrtc_vp8_dir)',
     'webrtc_vp9_dir%': '<(webrtc_vp9_dir)',
     'include_opus%': '<(include_opus)',
     'rtc_relative_path%': 1,
     'external_libraries%': '0',
     'json_root%': '<(DEPTH)/third_party/jsoncpp/source/include/',
     # openssl needs to be defined or gyp will complain. Is is only used when
@@ skipping 33 matching lines @@
     'build_libvpx%': 1,
     'build_libyuv%': 1,
     'build_openmax_dl%': 1,
     'build_opus%': 1,
     'build_ssl%': 1,
     'build_vp9%': 1,
 
     # Disable by default
     'have_dbus_glib%': 0,
 
-    # Enable to use the Mozilla internal settings.
-    'build_with_mozilla%': 0,
-
     # Make it possible to provide custom locations for some libraries.
     'libvpx_dir%': '<(DEPTH)/third_party/libvpx',
     'libyuv_dir%': '<(DEPTH)/third_party/libyuv',
     'opus_dir%': '<(opus_dir)',
 
     # Use Java based audio layer as default for Android.
     # Change this setting to 1 to use Open SL audio instead.
     # TODO(henrika): add support for Open SL ES.
     'enable_android_opensl%': 0,
 
@@ skipping 332 matching lines @@
           # of a more specific macro.
           'defines': [
             'WEBRTC_POSIX',
           ],
         }],
       ],
     },
   }, # target_defaults
 }