face: increment link layer byte counters in WebSocketFace

Change-Id: I88b7dea1cbd291765345982ce193700aacd73eb3
Refs: #1781
diff --git a/daemon/face/websocket-face.cpp b/daemon/face/websocket-face.cpp
index c0d6732..79faf73 100644
--- a/daemon/face/websocket-face.cpp
+++ b/daemon/face/websocket-face.cpp
@@ -48,6 +48,7 @@
 
   this->onSendInterest(interest);
   const Block& payload = interest.wireEncode();
+  this->getMutableCounters().getNOutBytes() += payload.size();
 
   try {
     m_server.send(m_handle, payload.wire(), payload.size(),
@@ -67,6 +68,7 @@
 
   this->onSendData(data);
   const Block& payload = data.wireEncode();
+  this->getMutableCounters().getNOutBytes() += payload.size();
 
   try {
     m_server.send(m_handle, payload.wire(), payload.size(),
@@ -97,6 +99,8 @@
   // Copy message into Face internal buffer
   BOOST_ASSERT(msg.size() <= MAX_NDN_PACKET_SIZE);
 
+  this->getMutableCounters().getNInBytes() += msg.size();
+
   // Try to parse message data
   bool isOk = true;
   Block element;