Bind a socket to a network if the network handle is set.

webrtc/p2p/base/basicpacketsocketfactory.cc

Index: webrtc/p2p/base/basicpacketsocketfactory.cc
diff --git a/webrtc/p2p/base/basicpacketsocketfactory.cc b/webrtc/p2p/base/basicpacketsocketfactory.cc
index 697518da9d0508cfcec888306b133514307726c7..e3c558783826ce9eba8d0abd999763c96f7ac7bb 100644
--- a/webrtc/p2p/base/basicpacketsocketfactory.cc
+++ b/webrtc/p2p/base/basicpacketsocketfactory.cc
@@ -16,6 +16,7 @@
 #include "webrtc/base/asyncudpsocket.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/nethelpers.h"
+#include "webrtc/base/network.h"
 #include "webrtc/base/physicalsocketserver.h"
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/base/socketadapters.h"
@@ -47,6 +48,14 @@ AsyncPacketSocket* BasicPacketSocketFactory::CreateUdpSocket(
     const SocketAddress& address,
     uint16_t min_port,
     uint16_t max_port) {
+  return CreateUdpSocketOnNetwork(address, min_port, max_port, nullptr);
+}
+
+AsyncPacketSocket* BasicPacketSocketFactory::CreateUdpSocketOnNetwork(
+    const SocketAddress& address,
+    uint16_t min_port,
+    uint16_t max_port,
+    const Network* network) {
   // UDP sockets are simple.
   rtc::AsyncSocket* socket =
       socket_factory()->CreateAsyncSocket(
@@ -54,6 +63,12 @@ AsyncPacketSocket* BasicPacketSocketFactory::CreateUdpSocket(
   if (!socket) {
     return NULL;
   }
+  if (network && network->IsHandleValid()) {
+    int res = socket->BindToNetwork(network->handle());
+    if (res < 0) {
+      LOG(LS_WARNING) << "Network bind failed with error " << res;
+    }
+  }
   if (BindSocket(socket, address, min_port, max_port) < 0) {
     LOG(LS_ERROR) << "UDP bind failed with error "
                     << socket->GetError();