Standardize "net" category trace events

net/quic/chromium/quic_stream_factory.cc

Index: net/quic/chromium/quic_stream_factory.cc
diff --git a/net/quic/chromium/quic_stream_factory.cc b/net/quic/chromium/quic_stream_factory.cc
index d7cc346de9363a753f88a469d51a8e862770d6e4..82b46af1c1025a1967e94a956289841a1d288e32 100644
--- a/net/quic/chromium/quic_stream_factory.cc
+++ b/net/quic/chromium/quic_stream_factory.cc
@@ -25,6 +25,7 @@
 #include "net/base/ip_address.h"
 #include "net/base/net_errors.h"
 #include "net/base/proxy_delegate.h"
+#include "net/base/trace_constants.h"
 #include "net/cert/cert_verifier.h"
 #include "net/cert/ct_verifier.h"
 #include "net/dns/host_resolver.h"
@@ -402,7 +403,7 @@ int QuicStreamFactory::Job::Run(const CompletionCallback& callback) {
 }
 
 int QuicStreamFactory::Job::DoLoop(int rv) {
-  TRACE_EVENT0("net", "QuicStreamFactory::Job::DoLoop");
+  TRACE_EVENT0(kNetTracingCategory, "QuicStreamFactory::Job::DoLoop");
   do {
     IoState state = io_state_;
     io_state_ = STATE_NONE;
@@ -1617,7 +1618,7 @@ int QuicStreamFactory::CreateSession(
 
     need_to_evaluate_consecutive_disabled_count_ = false;
   }
-  TRACE_EVENT0("net", "QuicStreamFactory::CreateSession");
+  TRACE_EVENT0(kNetTracingCategory, "QuicStreamFactory::CreateSession");
   IPEndPoint addr = *address_list.begin();
   bool enable_port_selection = enable_port_selection_;
   if (enable_port_selection && base::ContainsKey(gone_away_aliases_, key)) {