Enable the Java wrapper to load different .so library.

webrtc/sdk/android/BUILD.gn

 # Copyright (c) 2016 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("//webrtc/webrtc.gni")
 import("//build/config/android/config.gni")
@@ skipping 156 matching lines @@
     "api/org/webrtc/MediaCodecVideoDecoder.java",
     "api/org/webrtc/MediaCodecVideoEncoder.java",
     "api/org/webrtc/MediaConstraints.java",
     "api/org/webrtc/MediaSource.java",
     "api/org/webrtc/MediaStream.java",
     "api/org/webrtc/MediaStreamTrack.java",
     "api/org/webrtc/NetworkMonitor.java",
     "api/org/webrtc/NetworkMonitorAutoDetect.java",
     "api/org/webrtc/PeerConnection.java",
     "api/org/webrtc/PeerConnectionFactory.java",
+    "api/org/webrtc/PeerConnectionFactoryBase.java",
+    "api/org/webrtc/PeerConnectionFactoryDatachannelOnly.java",

[Taylor Brandstetter, 2017/05/11 10:17:11]

nit: I'd call the file "...DataChannelOnly.java", since "DataChannel" is
normally capitalized like that.

[Zhi Huang, 2017/05/12 00:35:47]

Done.

     "api/org/webrtc/RendererCommon.java",
     "api/org/webrtc/RTCStats.java",
     "api/org/webrtc/RTCStatsCollectorCallback.java",
     "api/org/webrtc/RTCStatsReport.java",
     "api/org/webrtc/RtpParameters.java",
     "api/org/webrtc/RtpReceiver.java",
     "api/org/webrtc/RtpSender.java",
     "api/org/webrtc/ScreenCapturerAndroid.java",
     "api/org/webrtc/SdpObserver.java",
     "api/org/webrtc/SessionDescription.java",
@@ skipping 65 matching lines @@
       "//third_party/android_support_test_runner:runner_java",
       "//third_party/junit",
       "//webrtc/base:base_java",
       "//webrtc/sdk/android:libjingle_peerconnection_java",
       "//webrtc/sdk/android:libjingle_peerconnection_metrics_default_java",
     ]
 
     shared_libraries = [ "//webrtc/sdk/android:libjingle_peerconnection_so" ]
   }
 }