Get the adapter type information from Android OS.

webrtc/base/network.cc

Index: webrtc/base/network.cc
diff --git a/webrtc/base/network.cc b/webrtc/base/network.cc
index 4525c3ccb6045f6b0ed8f9cc54c4ff64f452cef2..d0cffea42f8a4d5d98a934e3f1a9f6f4c4f27402 100644
--- a/webrtc/base/network.cc
+++ b/webrtc/base/network.cc
@@ -441,6 +441,8 @@ void BasicNetworkManager::ConvertIfAddrs(struct ifaddrs* interfaces,
       AdapterType adapter_type = ADAPTER_TYPE_UNKNOWN;
       if (cursor->ifa_flags & IFF_LOOPBACK) {
         adapter_type = ADAPTER_TYPE_LOOPBACK;
+      } else if (network_monitor_) {
+        adapter_type = network_monitor_->GetAdapterType(cursor->ifa_name);

[pthatcher1, 2016/01/19 02:13:07]

I'm still concerned about this being a blocking call.  If a new network coming
up causes a 20ms freeze in the network thread, that's 20ms of packets not
getting out.  I'd like to see if there's a way we can avoid this somehow.

[honghaiz3, 2016/01/21 21:38:36]

Removed the blocking part except that when the NetworkMonitor is started, it
will collect the network information once. 

       }
 #if defined(WEBRTC_IOS)
       // Cell networks are pdp_ipN on iOS.