Instrumenting callbacks of HttpNetworkTransaction to locate the source of jankiness

chrome/browser/devtools/devtools_network_transaction.cc

Index: chrome/browser/devtools/devtools_network_transaction.cc
diff --git a/chrome/browser/devtools/devtools_network_transaction.cc b/chrome/browser/devtools/devtools_network_transaction.cc
index 44111d77aee7e38503bd7ed078137b21e0ca2397..b6364914601dc2ac5d2ec086f7dad807d9f7f5f1 100644
--- a/chrome/browser/devtools/devtools_network_transaction.cc
+++ b/chrome/browser/devtools/devtools_network_transaction.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/devtools/devtools_network_transaction.h"
 
+#include "base/profiler/scoped_tracker.h"
 #include "chrome/browser/devtools/devtools_network_controller.h"
 #include "chrome/browser/devtools/devtools_network_interceptor.h"
 #include "net/base/net_errors.h"
@@ -54,6 +55,11 @@ void DevToolsNetworkTransaction::Throttle(int result) {
 }
 
 void DevToolsNetworkTransaction::OnCallback(int rv) {
+  // TODO(vadimt): Remove ScopedTracker below once crbug.com/424359 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "424359 DevToolsNetworkTransaction::OnCallback"));
+
   if (failed_)
     return;
   DCHECK(!callback_.is_null());