Add a new NetworkActivityMonitor to track network activity

net/udp/udp_socket_libevent.cc

Index: net/udp/udp_socket_libevent.cc
diff --git a/net/udp/udp_socket_libevent.cc b/net/udp/udp_socket_libevent.cc
index 9b1a9957189d968c3fed617ba02aa3ee7d13cb98..14c6472cd672e25aedc818fc52e8860bdb675e02 100644
--- a/net/udp/udp_socket_libevent.cc
+++ b/net/udp/udp_socket_libevent.cc
@@ -24,6 +24,7 @@
 #include "net/base/net_errors.h"
 #include "net/base/net_log.h"
 #include "net/base/net_util.h"
+#include "net/base/network_activity_monitor.h"
 #include "net/socket/socket_descriptor.h"
 #include "net/udp/udp_net_log_parameters.h"
 
@@ -414,6 +415,7 @@ void UDPSocketLibevent::LogRead(int result,
 
   base::StatsCounter read_bytes("udp.read_bytes");
   read_bytes.Add(result);
+  NetworkActivityMonitor::GetInstance()->AddBytesRead(result);
 }
 
 int UDPSocketLibevent::CreateSocket(int addr_family) {
@@ -458,6 +460,7 @@ void UDPSocketLibevent::LogWrite(int result,
 
   base::StatsCounter write_bytes("udp.write_bytes");
   write_bytes.Add(result);
+  NetworkActivityMonitor::GetInstance()->AddBytesWritten(result);
 }
 
 int UDPSocketLibevent::InternalRecvFrom(IOBuffer* buf, int buf_len,