Build WebRTC with data channel only.

webrtc/pc/BUILD.gn

Index: webrtc/pc/BUILD.gn
diff --git a/webrtc/pc/BUILD.gn b/webrtc/pc/BUILD.gn
index 10256ce2f407cc3b76e5ee3c28dfbde8188536be..78d77a47e7ac2ca3f51728ccd59183c91c940108 100644
--- a/webrtc/pc/BUILD.gn
+++ b/webrtc/pc/BUILD.gn
@@ -25,7 +25,7 @@ config("rtc_pc_config") {
   }
 }
 
-rtc_static_library("rtc_pc") {
+rtc_static_library("rtc_pc_base") {
   defines = []
   sources = [
     "audiomonitor.cc",
@@ -59,8 +59,9 @@ rtc_static_library("rtc_pc") {
     "../api:libjingle_peerconnection_api",
     "../api:ortc_api",
     "../base:rtc_base",
-    "../common_video:common_video",
-    "../media",
+    "../base:rtc_task_queue",
+    "../media:rtc_data",
+    "../media:rtc_media_base_data",
     "../p2p:rtc_p2p",
   ]
 
@@ -76,6 +77,18 @@ rtc_static_library("rtc_pc") {
   }
 }
 
+# TODO(zhihuang): Remove this once the downstream dependencies start using the
+# modular targets.
+rtc_source_set("rtc_pc") {
+  public_deps = [
+    ":rtc_pc_base",
+  ]
+
+  deps = [
+    "../media:rtc_audio_video",
+  ]
+}
+
 config("libjingle_peerconnection_warnings_config") {
   # GN orders flags on a target before flags from configs. The default config
   # adds these flags so to cancel them out they need to come from a config and
@@ -85,7 +98,7 @@ config("libjingle_peerconnection_warnings_config") {
   }
 }
 
-rtc_static_library("libjingle_peerconnection") {
+rtc_static_library("peerconnection") {
   cflags = []
   sources = [
     "audiotrack.cc",
@@ -146,19 +159,17 @@ rtc_static_library("libjingle_peerconnection") {
   }
 
   deps = [
-    ":rtc_pc",
+    ":rtc_pc_base",
     "..:webrtc_common",
     "../api:call_api",
     "../api:rtc_stats_api",
-    "../api/audio_codecs:builtin_audio_decoder_factory",
-    "../api/audio_codecs:builtin_audio_encoder_factory",
     "../api/video_codecs:video_codecs_api",
     "../base:rtc_base",
     "../base:rtc_base_approved",
-    "../call",
+    "../call:call_interfaces",
     "../logging:rtc_event_log_api",
-    "../media",
-    "../modules/audio_device:audio_device",
+    "../media:rtc_data",
+    "../media:rtc_media_base_data",
     "../p2p:rtc_p2p",
     "../stats",
     "../system_wrappers:system_wrappers",
@@ -167,6 +178,49 @@ rtc_static_library("libjingle_peerconnection") {
   public_deps = [
     "../api:libjingle_peerconnection_api",
   ]
+}
+
+# This target implements the CreatePeerConnectionFactory methods to build WebRTC
+# with full support(audio, video and datachannel). The applications would be
+# responsible to create their own implementation of CreatePeerConnectionFactory
+# methods with different dependencies based on their requirements.
+# The target "create_pc_factory_datachannelonly" is an example.

[the sun, 2017/06/13 14:34:38]

nit: comment referes to nonexistent target

[Zhi Huang, 2017/06/14 06:57:00]

Done.

+rtc_static_library("create_pc_factory") {
+  sources = [
+    "createpeerconnectionfactory.cc",
+  ]
+
+  deps = [
+    "../api:audio_mixer_api",
+    "../api:libjingle_peerconnection_api",
+    "../api/audio_codecs:audio_codecs_api",
+    "../api/audio_codecs:builtin_audio_decoder_factory",
+    "../api/audio_codecs:builtin_audio_encoder_factory",
+    "../base:rtc_base",
+    "../base:rtc_base_approved",
+    "../call",
+    "../call:call_interfaces",
+    "../logging:rtc_event_log_api",
+    "../media:rtc_audio_video",
+    "../modules/audio_device:audio_device",
+  ]
+
+  configs += [ ":libjingle_peerconnection_warnings_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" ]
+  }
+}
+
+# TODO(zhihuang): Remove this once the downstream dependencies start using the
+# modular targets.
+rtc_source_set("libjingle_peerconnection") {
+  public_deps = [
+    ":create_pc_factory",
+    ":peerconnection",
+    "../api:libjingle_peerconnection_api",
+  ]
 
   if (rtc_use_quic) {
     sources += [