Standardize "net" category trace events

net/url_request/url_request_http_job.cc

Index: net/url_request/url_request_http_job.cc
diff --git a/net/url_request/url_request_http_job.cc b/net/url_request/url_request_http_job.cc
index 6934c78006ce18b4cebbc351cbadcdc51345e17d..982208ef64690656650e706a417b7099df4f23b2 100644
--- a/net/url_request/url_request_http_job.cc
+++ b/net/url_request/url_request_http_job.cc
@@ -50,6 +50,7 @@
 #include "net/http/http_util.h"
 #include "net/log/net_log_event_type.h"
 #include "net/log/net_log_with_source.h"
+#include "net/log/trace_constants.h"
 #include "net/nqe/network_quality_estimator.h"
 #include "net/proxy/proxy_info.h"
 #include "net/proxy/proxy_retry_info.h"
@@ -855,8 +856,7 @@ void URLRequestHttpJob::ProcessExpectCTHeader() {
 }
 
 void URLRequestHttpJob::OnStartCompleted(int result) {
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("net"),
-               "URLRequestHttpJob::OnStartCompleted");
+  TRACE_EVENT0(kNetTracingCategory, "URLRequestHttpJob::OnStartCompleted");
   RecordTimer();
 
   // If the job is done (due to cancellation), can just ignore this
@@ -938,8 +938,7 @@ void URLRequestHttpJob::OnHeadersReceivedCallback(int result) {
 }
 
 void URLRequestHttpJob::OnReadCompleted(int result) {
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("net"),
-               "URLRequestHttpJob::OnReadCompleted");
+  TRACE_EVENT0(kNetTracingCategory, "URLRequestHttpJob::OnReadCompleted");
   read_in_progress_ = false;
 
   DCHECK_NE(ERR_IO_PENDING, result);