Build WebRTC with data channel only.

webrtc/webrtc.gni

 # 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/config/arm.gni")
 import("//build/config/features.gni")
@@ skipping 59 matching lines @@
   # Selects whether debug dumps for the audio processing module
   # should be generated.
   apm_debug_dump = false
 
   # Set this to true to enable BWE test logging.
   rtc_enable_bwe_test_logging = false
 
   # Set this to disable building with support for SCTP data channels.
   rtc_enable_sctp = true
 
+  # Set this to disable building audio and video stack.

[kjellander_webrtc, 2017/05/04 14:01:46]

"Set this to false to"...

[Zhi Huang, 2017/05/04 21:28:53]

Done.

+  rtc_enable_media = true
+
   # Disable these to not build components which can be externally provided.
   rtc_build_json = true
   rtc_build_libjpeg = true
   rtc_build_libsrtp = true
   rtc_build_libvpx = true
   rtc_libvpx_build_vp9 = true
   rtc_build_libyuv = true
   rtc_build_openmax_dl = true
   rtc_build_opus = true
   rtc_build_ssl = true
@@ skipping 278 matching lines @@
       configs += invoker.configs
       configs -= rtc_remove_configs
       configs -= invoker.suppressed_configs
       public_configs = [ rtc_common_inherited_config ]
       if (defined(invoker.public_configs)) {
         public_configs += invoker.public_configs
       }
     }
   }
 }