[NOT FOR LANDING] Detailed loading traces

net/http/http_response_headers.cc

Index: net/http/http_response_headers.cc
diff --git a/net/http/http_response_headers.cc b/net/http/http_response_headers.cc
index 2167aac2d820761738380b15f7346cdfc5705cbe..ff8e7a71282f6b2b70d5b12f6267aa7e3d6b06f5 100644
--- a/net/http/http_response_headers.cc
+++ b/net/http/http_response_headers.cc
@@ -12,6 +12,7 @@
 #include <algorithm>
 #include <utility>
 
+#include "base/trace_event/trace_event.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
@@ -1251,6 +1252,7 @@ bool HttpResponseHeaders::HasStrongValidators() const {
 // From RFC 2616:
 // Content-Length = "Content-Length" ":" 1*DIGIT
 int64_t HttpResponseHeaders::GetContentLength() const {
+  TRACE_EVENT0("toplevel", "HttpResponseHeaders::GetContentLength");
   return GetInt64HeaderValue("content-length");
 }