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

webrtc/p2p/base/packetsocketfactory.h

Index: webrtc/p2p/base/packetsocketfactory.h
diff --git a/webrtc/p2p/base/packetsocketfactory.h b/webrtc/p2p/base/packetsocketfactory.h
index 54037241b0a71ce26c5f4ac7afb4fdbb95073850..326f03ce0885c215f3bb61f5be5415d385823d19 100644
--- a/webrtc/p2p/base/packetsocketfactory.h
+++ b/webrtc/p2p/base/packetsocketfactory.h
@@ -11,12 +11,14 @@
 #ifndef WEBRTC_P2P_BASE_PACKETSOCKETFACTORY_H_
 #define WEBRTC_P2P_BASE_PACKETSOCKETFACTORY_H_
 
+#include "webrtc/base/common.h"
 #include "webrtc/base/proxyinfo.h"
 
 namespace rtc {
 
 class AsyncPacketSocket;
 class AsyncResolverInterface;
+class Network;
 
 class PacketSocketFactory {
  public:
@@ -32,6 +34,18 @@ class PacketSocketFactory {
   virtual AsyncPacketSocket* CreateUdpSocket(const SocketAddress& address,
                                              uint16_t min_port,
                                              uint16_t max_port) = 0;
+  // TODO(honghaiz): Make this pure virtual method when all subclasses in
+  // Chrome define this.
+  virtual AsyncPacketSocket* CreateUdpSocketOnNetwork(
+      const SocketAddress& address,
+      uint16_t min_port,
+      uint16_t max_port,
+      const Network* network) {
+    // Should not have reached here.
+    ASSERT(false);
+    return nullptr;
+  }
+
   virtual AsyncPacketSocket* CreateServerTcpSocket(
       const SocketAddress& local_address,
       uint16_t min_port,