Build WebRTC with data channel only.

webrtc/api/DEPS

 include_rules = [
   "+third_party/libyuv",
   "+webrtc/base",
   "+webrtc/common_video",
   "+webrtc/media",
   "+webrtc/p2p",
   "+webrtc/pc",
 ]
 
 specific_include_rules = {
   "peerconnection_jni\.cc": [
     "+webrtc/voice_engine",
   ],
 
   # TODO(ossu): Remove this exception when {builtin_,}audio_encoder_factory.h
   # has moved to api/.
   "peerconnectioninterface\.h": [
+    "+webrtc/call/callfactoryinterface.h",
+    "+webrtc/logging/rtc_event_log/rtc_event_log_factory_interface.h",
     "+webrtc/modules/audio_coding/codecs/audio_encoder_factory.h",
     "+webrtc/modules/audio_coding/codecs/builtin_audio_encoder_factory.h",
   ],
 
   # We allow .cc files in webrtc/api/ to #include a bunch of stuff
   # that's off-limits for the .h files. That's because .h files leak
   # their #includes to whoever's #including them, but .cc files do not
   # since no one #includes them.
   ".*\.cc": [
     "+webrtc/modules/audio_coding",
   ],
 }