Standardize "net" category trace events

net/socket/ssl_client_socket_impl.cc

Index: net/socket/ssl_client_socket_impl.cc
diff --git a/net/socket/ssl_client_socket_impl.cc b/net/socket/ssl_client_socket_impl.cc
index d20d81e2d12b8c4c8c29d4da2234a88d23f5d29c..92861d4f8342b2dd9c812cd2610aa5629abb3730 100644
--- a/net/socket/ssl_client_socket_impl.cc
+++ b/net/socket/ssl_client_socket_impl.cc
@@ -29,6 +29,7 @@
 #include "crypto/openssl_util.h"
 #include "net/base/ip_address.h"
 #include "net/base/net_errors.h"
+#include "net/base/trace_constants.h"
 #include "net/cert/cert_verifier.h"
 #include "net/cert/ct_ev_whitelist.h"
 #include "net/cert/ct_policy_enforcer.h"
@@ -1330,7 +1331,7 @@ void SSLClientSocketImpl::OnHandshakeIOComplete(int result) {
 }
 
 int SSLClientSocketImpl::DoHandshakeLoop(int last_io_result) {
-  TRACE_EVENT0("net", "SSLClientSocketImpl::DoHandshakeLoop");
+  TRACE_EVENT0(kNetTracingCategory, "SSLClientSocketImpl::DoHandshakeLoop");
   int rv = last_io_result;
   do {
     // Default to STATE_NONE for next state.