Build WebRTC with data channel only.

webrtc/sdk/android/BUILD.gn

Index: webrtc/sdk/android/BUILD.gn
diff --git a/webrtc/sdk/android/BUILD.gn b/webrtc/sdk/android/BUILD.gn
index 9fcedf907b7a5ce823aba7d243ef468c458179b3..6d51393b051f108e0483d957d36e7fb1199c5fcb 100644
--- a/webrtc/sdk/android/BUILD.gn
+++ b/webrtc/sdk/android/BUILD.gn
@@ -22,7 +22,70 @@ config("libjingle_peerconnection_jni_warnings_config") {
   }
 }
 
+rtc_static_library("libjingle_peerconnection_datachannel_only_jni") {

[sakal, 2017/05/11 11:06:12]

Can we just conditionally include files in the regular target if
rtc_enable_media is set?

[magjed_webrtc, 2017/05/11 13:02:02]

This approach does not look composable. Can we split up
libjingle_peerconnection_jni into multiple targets, i.e. audio, video, etc., and
let clients include the targets they need instead? We should also split up
peerconnection_jni.cc into many different files since it currently contains way
too much stuff.

[Zhi Huang, 2017/05/12 20:05:33]

Acknowledged.

I'll try to split it and remove all the ifdef. Otherwise we may still need
"datachannel_only" targets to compile same files with "datachannel_only" define
set.

[Zhi Huang, 2017/05/12 20:05:33]

I did that before but I realized that we can't do that because we don't have
flags like "rtc_enable_media" in internal build system. This is main motivation
to create parallel _datachannel_only targets.

+  sources = [
+    "src/jni/androidhistogram_jni.cc",
+    "src/jni/androidmediacodeccommon.h",
+    "src/jni/androidnetworkmonitor_jni.cc",
+    "src/jni/androidnetworkmonitor_jni.h",
+    "src/jni/classreferenceholder.cc",
+    "src/jni/classreferenceholder.h",
+    "src/jni/jni_helpers.cc",
+    "src/jni/jni_helpers.h",
+    "src/jni/peerconnection_jni.cc",
+    "src/jni/rtcstatscollectorcallbackwrapper.cc",
+    "src/jni/rtcstatscollectorcallbackwrapper.h",
+  ]
+
+  configs += [ ":libjingle_peerconnection_jni_warnings_config" ]
+
+  if (is_clang) {
+    # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
+    suppressed_configs += [
+      "//build/config/clang:extra_warnings",
+      "//build/config/clang:find_bad_constructs",
+    ]
+  }
+
+  # TODO(jschuh): Bug 1348: fix this warning.
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
+  if (is_win) {
+    cflags += [
+      "/wd4245",  # conversion from "int" to "size_t", signed/unsigned mismatch.
+      "/wd4389",  # signed/unsigned mismatch.
+    ]
+  }
+
+  deps = [
+    "../..:webrtc_common",
+    "../../base:rtc_base",
+    "../../base:rtc_base_approved",
+    "../../base:rtc_task_queue",
+    "../../media:rtc_media_base_datachannel_only",
+    "../../media:rtc_media_datachannel_only",
+    "../../modules/utility:utility",
+    "../../system_wrappers:system_wrappers",
+    "//webrtc/pc:libjingle_peerconnection_datachannel_only",
+  ]
+
+  if (rtc_build_libyuv) {
+    deps += [ "$rtc_libyuv_dir" ]
+    public_deps = [
+      "$rtc_libyuv_dir",
+    ]
+  } else {
+    # Need to add a directory normally exported by libyuv.
+    include_dirs = [ "$rtc_libyuv_dir/include" ]
+  }
+}
+
 rtc_static_library("libjingle_peerconnection_jni") {
+  defines = [
+    "HAVE_WEBRTC_VOICE",
+    "HAVE_WEBRTC_VIDEO",
+  ]
+
   sources = [
     "src/jni/androidhistogram_jni.cc",
     "src/jni/androidmediacodeccommon.h",
@@ -96,6 +159,23 @@ rtc_static_library("libjingle_peerconnection_jni") {
   }
 }
 
+rtc_static_library(
+    "libjingle_peerconnection_datachannel_only_metrics_default_jni") {
+  sources = [
+    "src/jni/androidmetrics_jni.cc",
+  ]
+
+  configs += [ ":libjingle_peerconnection_jni_warnings_config" ]
+
+  deps = [
+    ":libjingle_peerconnection_datachannel_only_jni",
+    "../../system_wrappers",
+    "//webrtc/pc:libjingle_peerconnection_datachannel_only",
+    "//webrtc/system_wrappers:field_trial_default",
+    "//webrtc/system_wrappers:metrics_default",
+  ]
+}
+
 rtc_static_library("libjingle_peerconnection_metrics_default_jni") {
   sources = [
     "src/jni/androidmetrics_jni.cc",
@@ -112,6 +192,23 @@ rtc_static_library("libjingle_peerconnection_metrics_default_jni") {
   ]
 }
 
+rtc_shared_library("libjingle_peerconnection_datachannel_only_so") {
+  sources = [
+    "src/jni/jni_onload.cc",
+  ]
+
+  suppressed_configs += [ "//build/config/android:hide_all_but_jni_onload" ]
+  configs += [ "//build/config/android:hide_all_but_jni" ]
+
+  deps = [
+    ":libjingle_peerconnection_datachannel_only_jni",
+    ":libjingle_peerconnection_datachannel_only_metrics_default_jni",
+    "../../base:rtc_base",
+    "//webrtc/pc:libjingle_peerconnection_datachannel_only",
+  ]
+  output_extension = "so"
+}
+
 rtc_shared_library("libjingle_peerconnection_so") {
   sources = [
     "src/jni/jni_onload.cc",