Adding instrumentation to locate the source of jankiness.

net/url_request/url_request_ftp_job.cc

Index: net/url_request/url_request_ftp_job.cc
diff --git a/net/url_request/url_request_ftp_job.cc b/net/url_request/url_request_ftp_job.cc
index d774714246e66fee311c84c8f26c3b3ace365dfc..d1050e332a5b60faafb49e2787f2fda695f2cec3 100644
--- a/net/url_request/url_request_ftp_job.cc
+++ b/net/url_request/url_request_ftp_job.cc
@@ -285,6 +285,11 @@ void URLRequestFtpJob::RestartTransactionWithAuth() {
 }
 
 LoadState URLRequestFtpJob::GetLoadState() const {
+  // TODO(pkasting): Remove ScopedTracker below once crbug.com/455952 is
+  // fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "455952 URLRequestFtpJob::GetLoadState"));
   if (proxy_info_.is_direct()) {
     return ftp_transaction_ ?
         ftp_transaction_->GetLoadState() : LOAD_STATE_IDLE;