Add P2PDatagramSocket and P2PStreamSocket interfaces.

remoting/signaling/xmpp_signal_strategy.cc

Index: remoting/signaling/xmpp_signal_strategy.cc
diff --git a/remoting/signaling/xmpp_signal_strategy.cc b/remoting/signaling/xmpp_signal_strategy.cc
index 9833c6bbea9aeb08b8693b835933adacdf304eb7..526de2fe17bcd97a5d8401434cfa6a8210be8d54 100644
--- a/remoting/signaling/xmpp_signal_strategy.cc
+++ b/remoting/signaling/xmpp_signal_strategy.cc
@@ -363,8 +363,9 @@ void XmppSignalStrategy::Core::OnSocketConnected(int result) {
   }
 
   writer_.reset(new BufferedSocketWriter());
-  writer_->Init(socket_.get(), base::Bind(&Core::OnNetworkError,
-                                          base::Unretained(this)));
+  writer_->Init(
+      base::Bind(&net::Socket::Write, base::Unretained(socket_.get())),
+      base::Bind(&Core::OnNetworkError, base::Unretained(this)));
 
   XmppLoginHandler::TlsMode tls_mode;
   if (xmpp_server_config_.use_tls) {
@@ -407,8 +408,9 @@ void XmppSignalStrategy::Core::OnTlsConnected(int result) {
   }
 
   writer_.reset(new BufferedSocketWriter());
-  writer_->Init(socket_.get(), base::Bind(&Core::OnNetworkError,
-                                          base::Unretained(this)));
+  writer_->Init(
+      base::Bind(&net::Socket::Write, base::Unretained(socket_.get())),
+      base::Bind(&Core::OnNetworkError, base::Unretained(this)));
 
   login_handler_->OnTlsStarted();