Adding instrumentation to locate the source of jankiness.

net/socket/ssl_client_socket_nss.cc

Index: net/socket/ssl_client_socket_nss.cc
diff --git a/net/socket/ssl_client_socket_nss.cc b/net/socket/ssl_client_socket_nss.cc
index 26725353384dbf993a11c8f9493cf5c6d2829024..6ed7a47025b94fe2d63e83d958eb77e4d1df176e 100644
--- a/net/socket/ssl_client_socket_nss.cc
+++ b/net/socket/ssl_client_socket_nss.cc
@@ -2628,6 +2628,11 @@ void SSLClientSocketNSS::Core::DidNSSWrite(int result) {
 }
 
 void SSLClientSocketNSS::Core::BufferSendComplete(int result) {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/418183 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "418183 DidCompleteReadWrite => Core::BufferSendComplete"));
+
   if (!OnNSSTaskRunner()) {
     if (detached_)
       return;
@@ -2671,6 +2676,11 @@ void SSLClientSocketNSS::Core::OnGetChannelIDComplete(int result) {
 void SSLClientSocketNSS::Core::BufferRecvComplete(
     IOBuffer* read_buffer,
     int result) {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/418183 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "418183 DidCompleteReadWrite => SSLClientSocketNSS::Core::..."));
+
   DCHECK(read_buffer);
 
   if (!OnNSSTaskRunner()) {